UNIVERSITY OF CALIFORNIA 
 
 COLLEGE OF AGRICULTURE 
 
 AGRICULTURAL EXPERIMENT STATION 
 
 CIRCULAR No. 276 
 
 March, 1924 
 
 HOME CANNING 
 
 By W. V. CliUESS and A. W. CHRISTIE 
 
 CONTENTS 
 
 PAGE 
 
 A. Principles of Canning 2 
 
 Causes of spoiling 2 
 
 Methods of preserving 3 
 
 Sterilizing fruit juices 4 
 
 Preservatives 4 
 
 Methods of home canning 5 
 
 B. Methods, Materials, and Equip- 
 
 ment 5 
 
 General equipment 5 
 
 Jars 6 
 
 Cans 7 
 
 Sealing sanitary cans 10 
 
 Preparation of materials 11 
 
 Packing of fruits 14 
 
 Blanching 15 
 
 Exhausting 15 
 
 Syrups 15 
 
 Brix and Balling sugar testers.... 15 
 
 Baum^ sugar tester 16 
 
 Strength of sjrups 16 
 
 Cane and beet sugar 17 
 
 Brines 17 
 
 Sterilizers 17 
 
 Marking 19 
 
 Storage and spoilage 19 
 
 C. Special Directions for Fruits 20 
 
 Apples 20 
 
 Pears, Peaches 20 
 
 Apricots 21 
 
 PAGE 
 
 Plums, Prunes 21 
 
 Cherries 21 
 
 Berries 21 
 
 Grapes 23 
 
 Figs 23 
 
 Rhubarb 23 
 
 Grape Fruit 26 
 
 Jelly Juices 26 
 
 Ripe Olives 26 
 
 D. Special Directions for Vege- 
 
 tables 28 
 
 Artichokes 28 
 
 Asparagus 29 
 
 Green Beans 29 
 
 Beets 30 
 
 Sweet corn 30 
 
 Peas 30 
 
 Peppers, Pimientos 30 
 
 Pumpkin 31 
 
 Tomatoes 31 
 
 Sweet Potatoes 31 
 
 Spinach 32 
 
 Okra 32 
 
 Soup mixtures 32 
 
 E. Special Directions for Meats 32 
 
 F. Ptomain and Botulinus Poison- 
 
 ing 34 
 
 G. Condensed Directions 36 
 
UNIVERSITY OF CALIFORNIA EXPERIMENT STATION 
 
 FOREWORD 
 
 This circular is based on Circular No. 158, "Home and Farm 
 Canning, ' ' but has been rearranged and almost completely rewritten. 
 By omitting matters of interest only to small canneries, and, by intro- 
 ducing new and improved methods specially adapted to the home, it 
 has been made more suitable for its primary purpose. The writers 
 desire to express their appreciation to Professor F. T. Bioletti, Dr. 
 K. F. Meyer, Dr. W. A. Magoon, Mr. A. Richardson, and others for 
 valuable suggestions given during the preparation and revision of the 
 manuscript. 
 
 A. PRINCIPLES OF CANNING 
 
 Requests for information on the home canning of fruits and 
 vegetables are received at the station with increasing frequency. To 
 supply this information it has been found necessary to test the 
 various methods generally recommended. This has been done both 
 with the utensils used in most kitchens and with special canning 
 equipment constructed for home and small-scale operations. This 
 circular is intended to describe approved methods and also to give 
 general information asked for by numerous inquirers. 
 
 A large quantity of fruits and vegetables goes to waste every year 
 or is sold at prices which return little profit. Much of this, while 
 unsuited to the special requirements of the commercial cannery, is 
 well adapted to canning for home use. The quality may be as good 
 as that of the products of commercial canneries or better if put up 
 with the proper knowledge and care. It is often possible to find a 
 limited market for home products of this kind at profitable prices. 
 
 Local and private markets are usually the most satisfactory for 
 the home or farm canner. He will seldom find it profitable to sell on 
 the general market through dealers in competition with commercial 
 canneries. With careful attention to all the details of the work and 
 a little business ability it will often be possible to make the home 
 canning outfit a profitable adjunct to the orchard and garden, and 
 much of the work will be found agreeable and profitable by the women 
 of the household. 
 
 Causes of Spoiling. — The principal aim of canning is to prevent 
 spoiling. Spoiling is not due directly to the action of air or of heat 
 and it is not simply a chemical nor a physical change. When vege- 
 table materials ferment, decay or turn sour, it is because of the growth 
 of certain microscopic, living organisms, or '' germs. '* These all 
 
Circular 276] HOME CANNING 3 
 
 belong to the vegetable kingdom and are divided into three groups: 
 molds, yeasts, and bacteria. Familiar examples of each group are 
 the blue-green mold of spoiled fruits, the yeast used in bread-making, 
 and the bacteria of the scum or ''mother" of vinegar. What we see 
 in compressed yeast, for instance, is simply a mass consisting of 
 millions of germs. Individual germs are too minute to be seen with- 
 out a microscope. Their activities cause the molding of jellies, the 
 swelling and souring of canned fruits and vegetables, and the putre- 
 fying of meats. The character of the material largely determines 
 which type of spoiling will occur. Acidity is favorable to yeasts and 
 molds. Fruits may therefore spoil by yeast fermentation or become 
 moldy. Bacteria prefer a medium with little or no acid. When vege- 
 tables or meats decay it is therefore usuallj'- due to the action of 
 bacteria. Neither fruits nor acid vegetables are favorable to the 
 growth of the bacteria which cause the putrefaction of meats. 
 
 Methods of Preserving. — The micro-organisms ("germs") which 
 cause spoiling come from the air or from the surfaces with which the 
 material comes in contact. They can no more develop from non-living 
 matter than wheat can appear spontaneously in soil devoid of wheat 
 seed. In food preservation, we are dealing with living organisms, 
 whose activities can be prevented in one of two ways : We may kill all 
 the germs present by heat or other means and prevent the entrance of 
 all others, or we may make the conditions so unfavorable to the germs 
 that they cannot grow or do any damage. The latter way is followed 
 when we impregnate meat with so much salt that bacteria cannot grow, 
 or add so much sugar to jam that yeast cannot multiply. The heat 
 method is utilized in most methods of canning. 
 
 Sterilization hy Heat. — The killing of all germs present is called 
 sterilization. In canning, this is accomplished by heating. The 
 material to be preserved is placed in a jar or can, in which it is sealed 
 hermetically, i.e., made air-tight. It is then heated to a temperature 
 fatal to all the germs it contains. No spoiling can then take place 
 until the vessel is opened, as there are no means by which germs 
 can enter. 
 
 Molds and yeasts, as they occur on fruits and vegetables, are 
 quickly killed at temperatures below 212° F., the boiling point of 
 water. In most cases, in fact, they are killed at temperatures between 
 150° F. and 180° F. On the other hand, bacteria occurring on 
 vegetables are much harder to kill, many of them withstanding the 
 temperature of boiling water for several hours. These bacteria owe 
 their astonishing resistance to the presence of spores. Spores are to 
 bacteria what seeds are to higher plants and are resistant to heat. 
 
4 UNIVERSITY OF CALIFORNIA EXPERIMENT STATION 
 
 These bacteria, with resistant spores, probably occur also on fruits, 
 but it is usually not necessary to kill them in this case, as they are 
 very sensitive to acidity and therefore cannot grow in fruit juices. 
 With vegetables the case is different. These, with the exception of 
 tomatoes, have little or no acidity and are well suited to the growth 
 of the heat-resistant bacteria. To sterilize vegetables it is therefore 
 usual to heat the sealed cans to temperatures above 212° F. The 
 temperature can be raised to 212° F. by placing the sealed cans in an 
 open tank or pot containing boiling water. But under these conditions 
 no higher temperature can be reached, as the evolving steam removes 
 the excess of heat as fast as it is applied. In a closed space where 
 the steam cannot escape, however, higher temperatures can be 
 obtained. As the • temperature rises the pressure increases. In can- 
 ning vegetables, pressures of five to fifteen pounds to the square inch 
 are generally used. This corresponds to temperatures of approxi- 
 mately 227° F. to 249° F.; the higher the pressure the higher the 
 temperature. 
 
 Sterilizing Fruit Juices. — Heating fruit juices to 212° F. always 
 changes the flavor more or less. In a few cases, this change of flavor 
 may be an improvement, but in most cases it is desirable to retain 
 as much of the original character of the juice as possible. This is 
 accomplished by careful handling and by heating to the lowest tem- 
 perature that will insure sterilization. Experiments continued for 
 two years at the Fruit Products Laboratory have shown that most 
 juices can be safely sterilized at temperatures of from 165° to 175° F. 
 See Circular 220, Unfermented Fruit Juices, for details of prepara- 
 tion. 
 
 Preservatives. — Food materials can be prevented from spoiling by 
 the use of certain substances known as preservatives. Some of these 
 are injurious to health and forbidden by the pure food laws. Others 
 are not encouraged by the pure food laws, because they are used by 
 unscrupulous manufacturers to disguise defective materials or care- 
 less methods of manufacture. The use in canning of such preserva- 
 tives as benzoate of soda, salicylic acid, sodium fluorid, boric acid, 
 etc., is condemned. 
 
 Certain preservatives, however, are useful and permissible. For 
 fruits, sugar is the preservative most commonly used. If the sugar 
 content of fruit juice, jelly or jam is raised to 65 per cent by evaporat- 
 ing part of the water, or by adding sugar, these products become 
 unsuitable to the growth of microorganisms and will keep even in 
 open vessels. This is why dried fruit does not spoil and why jam 
 must be made very sweet. 
 
Circular 276] 
 
 HOME CANNING 
 
 For some products salt is extensively used, as in preserving olives 
 in barrels and in keeping certain types of pickles. Vinegar and 
 spices are used in the same way. Sometimes a combination of the 
 effects of heat sterilization and harmless preservatives such as vinegar 
 is used in the preserving of pickles, etc. 
 
 METHODS OF HOME CANNING 
 
 The principles and theory of canning are the same whatever the 
 scale on which it is done. The differences are only in the mechanical 
 details of the methods of applying these principles. 
 
 There are two general methods in use. In one, known as the 
 "Hot-pack method," the material is cooked in open pots and poured 
 into the cans while hot, together with the hot brine or syrup. The 
 eans are sealed immediately, and may or may not be sterilized. In 
 the other, the ''Cold-pack method," the freshly prepared material is 
 placed cold in the cans and then covered with the hot syrup or brine, 
 sealed and sterilized. With both methods the material is always hot 
 when the cans are sealed. The cold-pack method is generally the best 
 for vegetables, while the hot-pack method can often be used to advan- 
 tage with fruits, if supplemented by sterilization in the container. 
 
 B. METHODS, MATERIALS, AND EQUIPMENT 
 
 General Equipment. — Most of the utensils and materials needed in 
 home-canning are to be found in all kitchens. They include a good 
 stove, or other means of heating, a table for the preparation of 
 materials, a sink and good supply of water, various agateware or 
 aluminum pots, saucepans, and buckets, large cooking spoons and a 
 sufficient supply of sugar and salt. To these should be added a good 
 thermometer, suitable for placing in liquids and reading to at least 
 250° F. (cost, about $1.50). A Balling or Brix saccharometer or 
 sugar tester is also very useful where fruit is to be canned on a farm 
 scale. It should read from to 70 per cent and costs about 75 cents. 
 For use with this will be needed a tin cylinder to hold the liquids 
 to be tested. It should be about IV2 inches in diameter and about 
 12 inches long (fig. 9). The thermometer and saccharometer can 
 often be obtained through a drug store or the local dealer. 
 
 Other necessary or desirable materials are described in the follow- 
 ing paragraphs. If the canning is to be done on a somewhat larger 
 scale for the market it will often be advisable to purchase a factory- 
 made outfit which may be obtained in various sizes. 
 
b UNIVERSITY OF CALIFORNIA EXPERIMENT STATION 
 
 Jars. — Glass jars are preferable to tin cans for home canning of 
 fruits because they can be used repeatedly. Their greater initial cost 
 is offset by this advantage. Where the product is to be sold, it is 
 usually necessary to use cans unless unusually high quality is de- 
 manded and a price sufficient to cover the extra cost of jars can be 
 obtained. 
 
 Fig. 1. — Types of jars used in home canning: (a) Eemovable clamp and glass 
 top; (h) fixed clamp and removable glass top; (c) lacquered metal clamp top; 
 (d) wide mouth and screw top of lacquered metal; (e) ordinary narrow mouth 
 and screw top, porcelain or glass-lined. 
 
 Glass jars are to be found in a variety of sizes and shapes and with 
 various methods of hermetic sealing. The sizes most used are pints 
 and quarts and to a smaller extent half -gallons. The only important 
 variation in shape is the width of the mouth which may be as wide 
 as the jar or only about half its width. The commonest method of 
 sealing is by means of a rubber ring w^hich fits between the cover and 
 the top of the jar (see fig. 1). 
 
 In the Mason jar and its various modifications the cover is a screw 
 cap which makes a hermetic joint when screwed dow^n on the rubber 
 ring. In the ordinary form this cap is of zinc with a porcelain lining. 
 This is the commonest and cheapest form. Aluminum and heavily 
 lacquered metal caps are to be preferred to zinc caps because of the 
 tendency of the zinc to corrode with sour fruits and tomatoes. Wide- 
 mouth Mason jars are now made which are very convenient for large 
 fruits. However, their large enameled metal caps are often difficult 
 to remove and may be broken in opening the jar. 
 
 In another common form, of which the Atlas '^E-Z" seal jar is 
 an example, the cover is a glass disc held in place and pressed down 
 on the rubber by means of a strong wire clamp. After the fruit 
 
Circular 276] HOME CANNING . 7 
 
 cools the clamp may be removed and the cover will be held in place 
 by the vacuum. This affords a convenient means of detecting^ spoiled 
 jars. If there is any fermentation of the fruit, the gas formed will 
 fill the vacuum and the cap will be loosened. This is a very convenient 
 and durable form of cover and there are no metal parts in contact 
 with the fruit. 
 
 Vacuum sealed glass jars are used in jelly and preserve factories. 
 They have enameled metal caps resting on heavy, soft rubber rings 
 and are held in place by a vacuum inside the jars. This vacuum is 
 produced by means of an expensive machine. For home use some 
 forms of these jars may be sealed by forcing the caps on by hand, 
 while the contents are hot. On cooling, a vacuum is produced which 
 holds the caps firmly in place. 
 
 In all cases where poor rubbers are used in sealing they must be 
 specially treated, as they will otherwise give a disagreeable taste to 
 the food. Fruit and vegetables are sometimes completely spoiled by 
 this taste. It can be avoided by thoroughly boiling the rubbers in 
 water made alkaline with two or three teaspoons of washing soda to 
 the quart. They are then rinsed and boiled a second time in water 
 made slightly acid with lemon juice or vinegar. A third short boiling 
 in plain water fits them for use. There are now several good brands 
 of jar rubbers which do not require this treatment. They can be 
 placed directly on the jars from the package. 
 
 In some forms of jars, the rubber ring is replaced by a ring or 
 disc of pasteboard treated or varnished. These are not commonly 
 used and are less generally suitable. 
 
 A commoner type that avoids the use of rubbers is the Economy 
 jar and its modifications. The cover is an enameled metal disc around 
 the edge of which runs a small groove filled with a hard wax-like com- 
 pound. When the jar and its contents are heated this compound 
 melts and seals the cover to the jar when it cools and hardens. A 
 metal spring holds the cover in place until the compound hardens and 
 may then be removed. This is jar "c" in figure 1. Considerable 
 difficulty has been met in using this jar because of failure of the caps 
 to seal the jars perfectly. 
 
 Cans. — There are three general types of cans used for fruit and 
 vegetables — the ''wax-top," the ''solder-top," and the "sanitary." 
 
 The cover of the "wax-top" can is sealed on by means of a ring 
 of hot sealing wax. It is suitable for use with fruits and tomatoes, 
 but it is not satisfactory for vegetables which require high tem- 
 peratures. The cans are easily manipulated and require no special 
 equipment. 
 
8 
 
 UNIVERSITY OF CALIFORNIA EXPERIMENT STATION 
 
 ''Solder-top" or ''stud-hole" cans with the necessary soldering 
 tools are used in the factory-made home canning outfits and can be 
 used with any outfit. The top of the can has a circular opening vary- 
 ing in width with the size and type of cans. After filling the can, this 
 opening is closed by soldering on a tin disc. This disc is usually 
 perforated with a small hole to allow steam to escape during the pre- 
 liminary heating. This hole must be closed with solder before the 
 final sterilization. (See fig. 2, G.) 
 
 Fig. 2. — Types of cans used in home canning: {A) No. 1 tall ''sanitary can; " 
 {B) No. 2 sanitary can; (C) No. 2^/2 sanitary can; (D) No. 3 sanitary can; 
 {E) No. 10 sanitary can; {F) quart size wax top can; (G) No. 2 solder top can. 
 
 "Sanitary cans" used in large canneries are not sealed with solder. 
 The cover or cap is "crimped" on by means of a special machine. 
 There is a rubber coating or paper gasket on the cap where it comes 
 in contact with the can, which makes the sealing doubly sure. Yqvj 
 satisfactory hand-power machines can be obtained at moderate cost. 
 
 Cans may be obtained which are coated inside with a protective 
 enamel. These are suitable for red fruits, berries and beets as they 
 minimize bleaching of the red color through action of the tin. 
 
 Cans versus Jars. — It is recommended that vegetables, except 
 tomatoes and rhubarb, be sterilized under steam pressure because of 
 the danger of food poisoning from those heated only at 212° F. (in 
 steam or boiling water). Unfortunately, glass jars are unsatisfactory 
 for use in a pressure sterilizer, because much of the liquid (brine or 
 syrup) boils out of the container, causing the jar after sterilization to 
 be only three-quarters or one-half filled with liquid. If the jars are 
 
Circular 27G] 
 
 HOME CANNING 
 
 tightly sealed to avoid this difficulty, many of them will })urst or many 
 of the rubbers will be forced away from the top, causing the jar to 
 leak. These difficulties are overcome in commercial canneries by the 
 use of compressed air in the pressure cookers, but this is not feasible 
 in the home. 
 
 Fig. 3. — Small hand power sealing machine for sanitary cans. 
 
 We have found that sanitary cans are the only satisfactory con- 
 tainers for vegetables to be sterilized under pressure in the home. 
 Where the quantity of vegetables is too small to warrant purchase 
 of a can sealer, it is possible for several families to join in the pur- 
 chase and use of such a machine. The cost is approximately $20.00. 
 
10 
 
 UNIVERSITY OF CALIFORNIA — EXPERIMENT STATION 
 
 Sealing Sanitary"' Cans. — Sanitary cans are more satisfactory for 
 home use than solder top cans for several reasons. Very little experi- 
 ence is required to obtain a perfect seal with the hand power sealers 
 used for sanitary cans. The opening of the can is wide, permitting 
 packing of large pieces of fruit or vegetables. The cans are readily 
 obtainable from can manufacturers, whereas solder top cans are now 
 difficult to obtain. There is no danger of fire or explosions in sealing 
 sanitary cans because the gasoline blow torch used in heating soldering 
 steels is not used. 
 
 / 
 
 firjt OperAtion Roll Cao 
 
 I I 
 
 ^ 
 
 firstOperjJionRoH' 
 
 1 
 
 
 1 1 
 
 
 
 
 li 
 
 1, 
 
 llli 
 
 IllMMUa^ 
 
 1 
 
 
 1 1 
 
 1 
 
 
 m\\\\\\\\\ 
 
 
 ■ "^ " 
 
 r 
 
 
 
 Second Oporif 
 
 on RoU^ 
 
 
 Fig. 4. — Sealing a sanitary can. (After Cruess and Christie Laboratory Manual 
 of Fruit and Vegetable Products.) 
 
 1. Lid in place before sealing. 
 
 2. Appearance of lid and edge of can after first operation. 
 
 3. Appearance after second operation. 
 
 * ' ' Sanitary " is a trade name and when applied to this type of can does not 
 imply that other cans are unsanitary. 
 
(JlKCLiLAR 276J HOME CANNING 11 
 
 111 using sanitary cans in home canning tlie prepared food is 
 packed into the washed can and boiling hot syrup or brine is added 
 to fill it. In commercial canning the can and contents are heated 
 in live steam or hot water for 4 to 10 minutes before sealing in order 
 to expel air from the food and liquid. While such preliminary heat- 
 ing is desirable it is not essential in home canning, provided the can 
 is filled with hoiling hot sprup or brine and sealed at once. 
 
 The general appearance and method of using a hand power sani- 
 tary can sealer are shown in fig. 3. To use the sealer proceed as 
 follows : 
 
 {a) Clamp the sealer to a stout table top as shown in fig. 3. Place 
 the lid on the can and set the can on the turn table. Raise the turn 
 table by swinging the elevating lever from the operator until it will go 
 no farther. 
 
 {!)) Turn the crank rapidly and at the same time push the seam- 
 ing roll lever very slowly away from the operator to bring the roll 
 number one against the top of the can until it will go no farther. 
 Fifteen turns of the crank should be sufficient. 
 
 (c) Continue turning the crank rapidly and pull the seaming roll 
 lever slowly toward the operator until it will go no farther. Give 
 the crank several more turns and remove the sealed can. 
 
 Fig. 4 illustrates the top of the can before sealing, after the first 
 seaming operation and after the final operation. Sealing a sanitary 
 can is spoken of as " double seaming. ' ' 
 
 Solder top cans are difficult to obtain at present and require con- 
 siderable skill in sealing. They are not recommended for home use. 
 
 PREPARATION OF MATERIALS 
 
 Nearly all fruits and vegetables require some kind of preparatory 
 treatment before canning. This may be washing, sizing, sorting for 
 color or ripeness, peeling, pitting, coring or slicing. In some cases 
 special machines or tools are necessary. Some simple tools generally 
 useful are show^n in figure 5. These are {A) a knife fitted with a 
 guard to prevent excessive waste of pulp in peeling, and a broad knife 
 {B) for cutting and slicing. For cling-stone peaches a special spoon 
 (0) with sharp edges is used. A curved spoon or knife (D) is used 
 for removing the cores of halved pears. Knife (^) is used for coring 
 apples. A cherry pitter is very useful. - See figure 8. Slicing and 
 cubing machines are available for vegetables. 
 
12 
 
 UNIVERSITY OF CALIFORNIA EXPERIMENT STATION 
 
 The Raw Materials.— With tlie exception of pears, fruits for can- 
 ning are best if tree ripened and canned as promptly after picking 
 as possible. Fruit purchased in the markets of large cities is usually 
 picked immature. It, therefore, is of poorer flavor than that which 
 is tree ripened, often lacks sugar, and may be more or less wilted or 
 overripe. City housewives will rarely find such fruit either economical 
 in price or equal to freshly picked ripe fruit in quality. 
 
 Fig. 5. — Knives used in canning: (A) peeling knife; (B) cutting knife; (6') 
 peach pitting spoon; (D) pear coring knife; (E) apple coring knife. 
 
 Vegetables as purchased in city markets are usually too costly for 
 home canning ; commercially canned vegetables are much cheaper. 
 Vegetables from city markets are apt also to be wilted or tough because 
 of standing after harvesting. Experience and experiments have 
 proven that such material is more difficult to sterilize than the freshly 
 picked products, because of contamination with resistant bacterial 
 spores, and therefore more liable to cause food poisoning when under- 
 
Circular 276] HOME CANNING 13 
 
 sterilized. Only freshly gathered vegetables from the home or farm 
 garden should be used for home canning ; for reasons of quality, 
 economy, and safety. 
 
 Preparation of Fruits. — General directions applicable to more than 
 one variety of fruit may most conveniently be given at this point. 
 
 Sorting and Grading. — Moldy and soured fruit should be discarded 
 — it is not only unfit for food but is more liable to develop botulinus 
 poison if improperly sterilized. 
 
 Overripe but sound fruit should be used for jam rather than for 
 canning. 
 
 If the canned product is to be sold, it should be carefully graded 
 for size, color, and maturity into two or three grades. These may be 
 designated First Quality (finest and most nearly perfect specimens), 
 Standard Quality (sound fruit of fair quality), and Pie Fruit (small, 
 slightly blemished, or overripe fruit). 
 
 Washing. — Clean fruit is essential to success. Wash all fruit 
 thoroughly before canning. 
 
 Hand Peeling. — If only small lots of fruit are to be canned, hand 
 peeling is the most practical method. A guarded knife such as that 
 shown in figure 5-A is desirable for soft fruits such as peaches and 
 pears, while the knife shown in figure 5-E is perhaps most satisfactory 
 for peeling and coring apples. 
 
 Mechanical Peeling. — If a relatively large quantity of apples is to 
 be canned, some form of mechanical peeler is desirable. Hardware 
 stores can supply an inexpensive hand power peeler for kitchen use. 
 A more expensive type peels and cores, or peels, cores, and slices the 
 apple in one operation. This is very useful for preparing apples 
 for drying. 
 
 Mechanical peelers for other fruits are not very satisfactory. 
 
 Lye Peeling. — To lye peel peaches or apricots, first prepare in an 
 agate ware or iron kettle (never aluminum) a lye solution of i/4 pound 
 (4 ounces or about 4 level tablespoons) of granulated lye, such as 
 Red Seal or Rex brands, in 2 gallons of water. Heat to boiling, and 
 while actively boiling immerse the peaches (halved clings or whole 
 freestones) or whole, apricots in a wire basket in the boiling solution 
 until the skin is loosened and i)artially dissolved. This will usually 
 require 30 to 60 seconds. Remove. Wash in water until skin and lye 
 are removed. Rinse thoroughly in fresh water. Washing away the 
 skin and lye under a jet of water from a faucet is nuicli more effective 
 and satisfactory than washing in still water. , 
 
14 UNIVERSITY OF CALIFORNIA — EXPERIMENT STATION 
 
 It will not be found worth while to attempt to lye peel small lots 
 of fruit, but the method will save a great deal of time if 50 pounds 
 of fruit or more is to be peeled. Lye peeled fruit should be canned 
 at once to avoid undue darkening. 
 
 Coring and Pitting. — Pears are peeled, cut in half, and the core 
 is then removed by the knife shown in figure 5-D or by means of a 
 sharp teaspoon. 
 
 Dessert cherries are usually canned without pitting, but sour or 
 sweet cherries intended for use in pies should be pitted before can- 
 ning. A mechanical pitter, such as that shown in figure 8, is more 
 convenient than the small pitters operated by the thumb and two 
 fingers. 
 
 Cling peaches are difficult to pit unless the spoon shown in figure 
 5-C is used. To use this spoon, first cut the peach to the pit com- 
 pletely around the suture ('* crease"). Insert the pitting knife (also 
 known as pitting spoon) from the stem end of the peach until the 
 point of the spoon rests at the blossom end of the pit. Rotate the 
 knife until one half of the peach separates. Then scoop the pit from 
 the other half. Pitting is best done before peeling. 
 
 Freestone peaches and apricots need only be cut in half and the 
 pit removed with the point of the cutting knife. 
 
 Peeling Vegetables. — Tomatoes are readily peeled after immersion 
 in boiling water for about one minute and chilling in cold water. The 
 cores should be removed at the same time, but if possible without 
 opening the seed sacs. 
 
 Beets require about 10 to 15 minutes boiling to loosen the skin ; 
 sweet potatoes require a longer time. Other root vegetables are peeled 
 by hand without preliminary heating. 
 
 Mechanical peelers for vegetables are too costly for home use. 
 
 Packing Fruit. — Most fruits may be packed into jars or cans after 
 preparation and without previous blanching or cooking. They should 
 be arranged to present a neat appearance in the jars. 
 
 Some fruits soften during sterilizing and give partially filled 
 containers, unless partially cooked before packing. Berries for this 
 reason should be cooked with an equal weight of sugar before packing. 
 This is best done by adding the dry sugar to the fruit in a preserving 
 kettle, bringing to a boil and boiling gently 3-4 minutes. The juice 
 of the fruit forms a syrup with the sugar — usually an excess of syrup 
 unless the mixture be allowed to stand overnight to permit absorption 
 of the syrup by the fruit. It may then be packed and sterilized in 
 the jars or cans. 
 
CiKCULAR 27GJ HOME CANNING 15 
 
 Apples should be cooked in boiling water and apricots in boiling 
 dilute syrup 3-4 minutes to soften them and cause shrinkage. They 
 may then be packed hot. If this is not done, the jars will be only 
 partially full after sterilization. 
 
 All fruits, in order to conserve can and jar space, may be cooked 
 a short time with sugar and a small amount of water as shown in 
 figure 9. Some home canners prefer this to the cold pack method. 
 The objection to it is that some fruits become broken and present a 
 less attractive appearance than cold packed fruit. 
 
 Cold packing of the raw fruit is recommended for peaches, pears, 
 plums, prunes, and cherries. 
 
 Blanching. — Certain vegetables should be ''blanched" or parboiled 
 before canning. This is done by dipping them in boiling water or 
 heating in steam. A wire screen basket or a frying basket, such as is 
 used in cooking doughnuts, will serve to hold the vegetables while they 
 are dipped in a large cooking pot containing boiling water. This 
 treatment improves the quality, by removing slimy matters and lessen- 
 ing the astringent taste of the skins. It is necessary with asparagus to 
 remove bitterness. Blanching also softens the vegetables so that a 
 larger amount may be packed into the jar or can. 
 
 Apples and apricots should also be blanched as described above in 
 order that a full can may be obtained. 
 
 Exhausting. — This process is desirable with nearly all air-tight 
 containers which are to be sterilized by heat. It consists of a prelim- 
 inary heating before sealing and before the final sterilization. It 
 results in expanding the air inside the container and thus driving out 
 most of it. When the sealed container and its contents cool, the small 
 amount of air still enclosed contracts and produces a partial vacuum. 
 If cans are sealed while the contents are cool they will swell on heat- 
 ing, owing to the expansion of the heated air. Exhausting is not 
 necessary with jars. If cans are packed with hot products, boiling 
 hot syrup or brine added and the cans sealed at once, exhausting can 
 be omitted in home canning. If merely warm or cold brine or syrup 
 is added, the can and contents should be heated in live steam- or boil- 
 ing water for at least five minutes before sealing. 
 
 Syrups. — Fruits are canned in sugar syrups of various strengths or 
 concentrations. In general, the more acid fruits require the most 
 sugar. The appropriate strengths are given in the directions for 
 canning the various fruits. 
 
 Brix or Balling Sugar Testers. — Syrups of the desired strengths 
 may be made up by weighing the sugar and measuring the water, 
 or by adding sugar to the water until the desired strength is indicated 
 
16 
 
 UNIVERSITY OF CALIFORNIA EXPERIMENT STATION 
 
 by the sugar tester or hydrometer. This is sometimes called a sac- 
 charometer and the commonest forms are the Brix and the Balling. 
 The hydrometer is floated in a sample of the syrup contained in a tall, 
 
 narrow metal or glass cjdinder and the 
 per cent of sugar read from the scale at 
 the surface of the liquid. If the syrup 
 is cold the reading is correct enough for 
 the purpose, but if very hot the reading 
 may be several per cent too high. (See 
 fig. 6.) 
 
 Baume Sugar Tester. — This is a 
 hydrometer similar in form to the Brix, 
 differing only in the scale, which reads 
 in degrees instead of per cent. The de- 
 grees may be multiplied by two to give 
 the per cent approximately. 
 
 Strength of Syrups, — For all prac- 
 tical purposes syrups for home canning 
 may be prepared with the following pro- 
 portions of sugar and water : Light 
 Syrup, 1 cup sugar to 4 cups of water; 
 Medium, 1 cup of sugar to two of water ; 
 and Heavy, 1% cups of sugar to 1 of 
 Avater. 
 
 By carefully measuring the sugar 
 and water, syrups of any desired 
 strength can be made. The following 
 table shows the relation between the 
 sugar per cent, Brix or Balling, the 
 Baume degree and the proportion of 
 sugar and water: 
 
 ^H 
 
 19 mi 
 
 Fig. 6. — Cylinder, thermom- 
 eter, and Balling sugar tester. 
 The tester in the cylinder of 
 syrup is read at the surface of 
 the liquid. In the illustration 
 this is approximately 12 per 
 cent. 
 
 
 
 SUGAE 
 
 SYEUPS 
 
 
 
 
 Per cent of si 
 
 igar 
 
 Baume 
 
 
 Weight of i 
 
 iugar added 
 
 (Brix or Ball 
 
 ng) 
 
 degrees 
 
 
 to 1 gal. 
 
 of water 
 
 10 
 
 
 5.5 
 
 
 
 
 lbs. 
 
 15 oz. 
 
 20 
 
 
 11.0 
 
 
 2 
 
 
 2 
 
 30 
 
 
 16.5 
 
 
 3 
 
 
 10 
 
 40 
 
 
 22.0 
 
 
 5 
 
 
 10 
 
 50 
 
 
 27.0 
 
 
 8 
 
 
 6 
 
 60 
 
 
 32.5 
 
 
 12 
 
 
 10 
 
 65 
 
 
 35.0 
 
 
 15 
 
 
 11 
 
Circular 27()J HOME CANxVING 17 
 
 In making' syrups accordinji^ to this table, the weight of sugar in 
 the last two columns opposite the desired per cent or degree is added 
 to each gallon oi* water and dissolved by warming and stirring. The 
 volume of syrup obtained is greater than that of the water used. The 
 increase of volume is very slight with syrups of 5 to 15 per cent, but 
 is greater with more concentrated syrups ; 15 pounds 11 ounces of 
 sugar and 1 gallon of water giving nearly 2 gallons of syrup at 65 
 per cent. For one quart of water use one-fourth the amounts of sugar 
 noted above. 
 
 Cane and Beet Sugar. — In numerous tests made by the Fruit 
 Products Laboratory, beet sugar was found to give results equal to 
 those of cane sugar. The prejudice against beet sugar is no longer 
 warranted as it is now produced in as pure a state as cane sugar, with 
 which it is identical chemically. Beet sugar is equally as good as cane 
 sug-ar for jellies and preserves and is used by many canners and 
 preservers. 
 
 Adding the Syrup. — The syrup should be boiled, strained to 
 remove solid impurities and poured into the jar or can boiling hot. 
 
 Brines. — For most canned vegetables a brine of about 2 per cent 
 salt is used. This corresponds to about 21/2 ounces or about 5 level 
 tablespoons of salt per gallon of water. Unless otherwise directed, 
 this brine, boiling hot, should be used to fill all cans of vegetables. 
 
 Sterilizers. — A sterilizer is a vessel in which the filled cans or jars 
 are heated to the degree and for the time necessary to sterilize their 
 contents. 
 
 Sterilizer for 212° F. — The sterilizer containing the cans and sev- 
 eral inches of water is placed on a stove, and steam generated by 
 boiling the water heats the cans. The cover must be sufficiently close 
 to insure steam heat in all parts of the vessel, but must not be too 
 tight, or the steam pressure will cause the vessel to burst. An 
 ordinary wash boiler fitting the top of a kitchen stove can be made 
 to serve as a very satisfactory home sterilizer. A piece of heavy wire 
 screen of half -inch mesh or a wooden rack cut to fit should be placed 
 in the bottom. This will serve to keep the jars from contact with the 
 bottom of the boiler, where they might break if too close to the fire. 
 Inexpensive jar racks to be used in wash boiler sterilizers are now 
 obtainable at any hardware store. Such a rack is shown in figure 9. 
 
 Cans may be placed in two or more tiers, separated and supported 
 by slat gratings w^hich allow the steam to penetrate to all parts of 
 every can. The cover of the boiler should fit snugly in order that 
 the steam will be confined and heat the upper part of the sterilizer 
 
18 UNIVERSITY OP CALIFORNIA EXPERIMENT STATION 
 
 to the boiling temperature. A cloth should be placed between the 
 cover and the top of the boiler if the cover does not fit tightly. See 
 figure 10. 
 
 Count time after the water hoils. 
 
 Pressure Sterilizers. — Certain vegetables are difficult to sterilize 
 except at very high temperatures. Sterilizers using high pressure 
 steam will attain these temperatures and the cheapest forms can be 
 bought for about $18. See figure 11. 
 
 Where vegetables and meat are to be canned for sale it will usually 
 pay to obtain a pressure cooker, as they are fairly easy to operate. 
 Directions for operating accompany the outfits. 
 
 The pressure cooker is fitted with steam gauge, thermometer, 
 release cock and safety valve with weight and lever to regulate the 
 pressure. In using it about 3 inches of hot water is added. The 
 sealed cans are then placed in the crate and lowered into the sterilizer. 
 The cover of the cooker is now screwed down, but the release cock is 
 left open. Heat is then applied until steam escapes freely from the 
 open cock. This cock is then closed and heating continued until the 
 temperature reaches the desired point. At this point the safety valve, 
 weight and lever should be set for the corresponding pressure. At 
 the same time the release cock is opened slightly, so as to allow a 
 small escape of excess steam. By this means the temperature can be 
 regulated very exactly. The safety valve will open and relieve the 
 pressure if the temperature commences to go too high. When the 
 heating has continued for the required time, the cooker is removed 
 from the fire, the release cock opened full, and when the pressure has 
 fallen to the cans are removed and cooled in w^ater. If the cooker 
 is opened before the pressure has fallen to 0, steam may scald the 
 operator. The larger outfits of this kind are equipped with a small 
 steam boiler for heating, and three or more cookers. Pressure steril- 
 izers are usually operated at 5, 10, or 15 pounds pressure, correspond- 
 ing to 227° F., 239° F., and 249° F., respectively. 
 
 Closing and Cooling Jars and Cans. — After the sterilizing period 
 is completed in the 212° F. sterilizer or after the pressure in the 
 pressure cooker has fallen to 0, with the release valve closed, remove 
 the jars; screw or clamp the tops tightly and invert jars to cool in a 
 room free from cold drafts. The exceptions to this rule are Economy 
 and similar jars with composition tops — clamp the tops of these 
 tightly but do not invert. 
 
 Cans are sealed before sterilization; and are removed and chilled 
 to about blood temperature in cold water after sterilization. With 
 
Circular 276] HOME CANNING 19 
 
 cans the release valve may be opened immediately after the steriliza- 
 tion period is complete. 
 
 Marking Cans and Jars. — All containers should be plainly marked 
 with the variety and grade of the product. This can be done by means 
 of a small set of rubber stamps and canner's ink, which will stand 
 hot water. They may also be marked after sterilization with gummed 
 labels or wax pencils specially made for writing on tin and glass. 
 The name of the fruit and some such mark as A or 1 for first and B 
 or 2 for second grade on the bottom of the can will serve to identify 
 them. India ink is satisfactory for stamping or marking cans. 
 
 All lots should be dated so that the containers of each lot may be 
 identified later, and a short record giving the time of sterilization in 
 each case should be kept for future reference. Such labeling and 
 records will be found very valuable in locating the cause of spoilage, 
 should this occur. 
 
 Storage and Spoilage. — Before any canned fruit is put on the 
 market, it should be stored at least a month to see if it will show 
 spoilage. It is better to have cans spoil in the storeroom than on the 
 grocers' shelves. If the fire used to heat the sterilizer is not hot 
 enough, it may take too long to bring the cans to the temperature of 
 boiling water and the ''germs" that cause spoilage may not be killed. 
 Often, however, the trouble is due to leaks in the cans. With an 
 inexperienced operator, leaks often occur around the seam of sanitary 
 cans or in the solder groove of the cap of solder top cans. When the 
 capping operation is well done, there should be very few leaks. Leaks 
 can be detected by bubbles appearing when the cans are dropped into 
 hot water. Leaks permit air to enter and the air brings with it 
 "germs" which cause the fruit or other product to ferment or spoil 
 and produce the gas that causes the cans to swell. Jars should be 
 wrapped in paper to exclude light and stored in a cool place. 
 
 Spoiled cans or jars of food should never be tasted or used. They 
 may contain Bacillus hotulimis, and be deadly poisonous. Do not feed 
 spoiled canned food to fowls or animals — it may poison them. Many 
 cases of poisoning of chickens by spoiled home canned foods are on 
 record. See also discussion of Ptomain and Botulinus poisoning, 
 page 34. 
 
20 UNIVERSITY OF CALIFORNIA EXPERIMENT STATION 
 
 C. SPECIAL DIRECTIONS FOR FRUITS 
 
 Apples. — Canned apples are used principally for pies. Any variety 
 v^ill do for this purpose, but canners in California are limited largely 
 to Bellflowers, Newtown Pippins, and Gravensteins, as these are the 
 chief varieties grown in the state and available culls are chiefly of 
 these varieties. 
 
 Peel; core; quarter; blanch in boiling water 3-4 minutes; pack 
 hot; fill with boiling water, and process as directed in Table 1. 
 
 Apple Sauce. — Prepare as for the table. Pack scalding hot into 
 cans. Sterilize as for apples. 
 
 Pears. — The Bartlett is the best variety for canning purposes. 
 Fruit for canning is harvested while still green but after it has 
 reached full size. It is allowed to ripen in boxes. When canned, it 
 should be of good size and prime ripe, but not too soft. The fruit is 
 peeled by hand and cored by the coring knife shown in figure 5-D. 
 
 As pears tend to turn brown rapidly after peeling, they should be 
 placed in the can with syrup as soon as peeled, or should be kept under 
 water or dilue brine (2 tablespoons of salt per gallon of water) after 
 peeling until used. Pack into jars or cans and add hot medium or 
 light syrup. See Table 1 for sterilization. 
 
 Peaches. — For canning, peaches must have a good flavor which 
 remains after heating ; the texture must be close and the fiber tender ; 
 the color should be an even yellow and the ripening uniform from 
 surface to pit. Of the cling varieties, the Tuscan and Phillips are very 
 satisfactory, and of the freestones, the Lovell, Muir, Crawford, and 
 Elberta are preferred. 
 
 Peel and pit as directed on page 11. Pack in cans or jars and 
 add hot Medium or Heavy syrup. See also table 1 for further 
 directions. 
 
 Peaches may be canned in a plain syrup or in a sweet spiced 
 vinegar made as follows : 
 
 Sugar 3% lbs 
 
 Vinegar 1 pint 
 
 Water 1 pint 
 
 Ginger root i/i oz. 
 
 Whole cloves i^ oz. 
 
 Stick cinnamon % oz. 
 
 Bring this mixture to boiling. Let stand over night to absorb spice 
 flavor. Strain and add boiling hot to the jar or can. 
 
 If full jars or cans are desired the fruit may be prepared and 
 canned as directed in the hot-pack method shown in figs. 9 and 10. 
 
Circular 276] 
 
 HOME CANNING 
 
 21 
 
 Apricots. — Apricots for canning should be rix)e and well colored, 
 but not too soft. Many canners make the mistake of canning apricots 
 too green. The canned product from such fruit has a ''green" 
 astringent taste that no amount of sugar can wholly overcome. If 
 over-ripe, on the other hand, the fruit 
 cooks down to a jam of unattractive 
 appearance. Blanching for 3-4 minutes 
 in boiling syrup before packing is de- 
 sirable. 
 
 Apricots require a heavy syrup to 
 bring out their best flavor. See table 1 
 for further directions. 
 
 Plums. — This fruit is canned whole. 
 On account of the plum's high acidity, 
 glass is to be preferred to tin. 
 
 The fruit should be picked when it is 
 beginning to turn soft. If too ripe, it 
 will cook down to a jam in the can and 
 if too green will be too sour and lacking 
 in flavor. Blanching, as with apricots, 
 before canning is desirable. Pack in 
 cans or jars and add a Medium or 
 Heavy syrup. See also table 1 for sterilization. 
 
 Fresh Prunes. — Fresh California prunes are not canned commer- 
 cially, but are perhaps preferable to dried prunes for home use. Select 
 well colored ripe prunes of large size. Wash and place in cans. Add 
 Medium syrup (40 per cent) hot. See table 1 for sterilization. 
 
 Cherries — Cherries canned without pitting develop a ''bitter 
 almond" or "pit" flavor, pleasing to some and disagreeable to others. 
 Small hand-pitting machines can be obtained from any hardware store 
 for a small price. (See fig. 8.) All pitting machines remove the pits 
 by means of a cross-shaped plunger which laterates the flesh more or 
 less, and, therefore, the fruit must be canned immediately after pitting 
 to check deterioration. The Royal Anne, a large white cherry, is 
 seldom pitted. Cherries tend to shrivel in heavy syrups or if covered 
 with hot syrups. Only moderately sweet syrups should be used, there- 
 fore, and the cans exhausted by heating in boiling water or steam for 5 
 minutes before sealing, rather than exhausted after adding hot syrup. 
 See table 1. 
 
 Blackberries. — Blackberries shrink during cooking and the fruit 
 which fills a can when fresh will shrink to about two-thirds or less 
 
 Fia-. 
 
 '. — Funnel for filling fruit 
 and syrup into jars. 
 
22 
 
 UNIVERSITY OF CALIFORNIA EXPERIMENT STATION 
 
 after sterilizing. If the cans are to be well filled, the blackberries 
 must first be cooked. 
 
 To each pound of fruit add one pound or less of sugar, according 
 to the ripeness of the fruit. Boil with gentle stirring for about 3 to 
 4 minutes. Pack into cans or jars scalding hot. Seal cans. Sterilize 
 cans at the boiling point for 5 minutes. Lacquered cans or glass jars 
 must be used for all berries, because plain tin bleaches the color of 
 the fruit. The extra syrup formed by the juice of the fruit can be 
 used on the next lot or the excess moisture may be boiled off and the 
 fruit made into a preserve before canning. 
 
 Fig. 8. — Small hand x^ower cherry pitting machine for home use. 
 
 An alternative method is to cook with sugar, as directed, and 
 store over night. Heat to boiling, and proceed as above. 
 
 Loganberries. — Loganberries may be canned by practically the 
 same method as recommended for blackberries. Lacquered cans or 
 glass jars must be used. 
 
 Raspberries. — Raspberries may be canned as directed for black- 
 berries. 
 
 Strawberries. — These berries shrink very badly in volume if 
 cooked in the can. Therefore, proceed as for blackberries after 
 hulling. 
 
(JlKCULAR 276J HOME CANNING 23 
 
 Currants, Cranberries, Gooseberries. — These I'm its are used only 
 for pies, jellies, and jams, and are not commonly canned. They may 
 be put up in enameled cans or in jars in plain water and sterilized 
 at 212° F. No sugar need be used, although the flavor of the fruit 
 is better if canned in syrup instead of water. 8ee table 1. 
 
 Grapes. — Muscat grapes are canned commercially in considerable 
 quantities in California. The thoroughly ripe grapes are removed 
 from the stems and graded for size and appearance. Pack in cans 
 or jars and add Medium or Light syrup. The canned fruit is used 
 for pies. See also table 1. 
 
 Figs. — Figs are usually put in glass in the form of preserves. The 
 fruit should be allowed to ripen thoroughly on the tree and must be 
 handled carefully during picking and transferring to the cannery. 
 
 In commercial canning, figs are graded, washed and then blanched 
 3 to 4 minutes in hot water. They are then placed in the cans in a 
 very heavy syrup (70° Balling) and are cooked in the sealed cans 
 for about two hours at the boiling point. This method many be used 
 in the home also. 
 
 For home use, the following method may be used : Grade the figs 
 according to size. After cutting off the stems, the fruit is weighed 
 and placed in a preserve kettle. For each pound of fruit, add 1 pound 
 of sugar and 2 pints water. Boil down sloAvly until the hot syrup 
 will test about 55-60° Balling or 33° Baume, or until the mixture 
 reaches a boiling point 8° above the boiling point of water, which is 
 for most localities 220° F., or until the fruit is well cooked and of a 
 consistency of a heavy preserve. Jars, with their caps and rubbers, 
 are scalded by heating in boiling water. They are then filled with the 
 boiling hot preserve and the caps screwed down loosely. As soon as 
 filled the jars should be placed in hot water and sterilized at the 
 boiling point for 25 to 30 minutes. Figs may be put up in cans in 
 a similar manner. The Kadota, White Endich and other figs with 
 few seeds and thick flesh are best suited to preserving, although the 
 Mission, Calimyrna and White Adriatic may be used. 
 
 Rhubarb. — From a culinary point of view, rhubarb is a fruit and 
 is very easily sterilized and canned in the same general w^ay as fruits. 
 Since it is used chiefly as a pie stock no sugar need be used. 
 
 Wash the stalks; cut into short lengths and place in a stewpan, 
 with a little water. Boil until soft. Pack boiling hot into cans or 
 jars and seal. See table 1 for sterilizing. 
 
 Tin cans are soon badly corroded by rhu])arb and prefi^'ably only 
 glass should be used. 
 
24 
 
 UNIVERSITY OF CALIFORNIA EXPERIMENT STATION 
 
 1. Preparation of the fruit. 
 — Wash, sort and prepare 
 the fruit as for cooking. Ee- 
 move peel, cores, and pits; 
 cut or slice as desired. Cook 
 as soon as possible after cut- 
 ting. To prevent darkening, 
 cut apples and pears should 
 1)6 kept in water until 
 cooked. 
 
 2. Heating and cooMng 
 with sugar. — Place the pre- 
 pared fruit in a pot and 
 then add dry sugar, Y^ to % 
 lb. per pound of fruit, or 
 with very sweet fruit none. 
 Add a little water to firm 
 fruits to avoid scorching. 
 Add no water to berries. 
 Heat to scalding tempera- 
 ture. Do not cook till soft. 
 Peaches, pears, cherries, 
 grapes, and some other firm 
 fruits may be canned with- 
 out this preliminary cook- 
 ing. 
 
 3. Filling the jars. — Warm 
 the jars with hot water, and 
 ladle the hot fruit into them 
 through a funnel until they 
 are filled to within 1^4 inch 
 of the top. Avoid getting 
 juice on the outside. The 
 neck should be dry and clean. 
 Or pack uncooked firm fruits 
 into jars cold. Add hot 
 syrup and proceed as in 
 steps 4-7. 
 
 Fig. 9, — Preparing fruits for modified hot pack process. 
 
4. Tlacing ruhbers and 
 covers. — Test clean scalded, 
 rubbers by bending and 
 stretching. They should not 
 crack. Put evenly in place 
 on the necks of the jar, then 
 apply the covers, placing or 
 screwing them loosely, and 
 lower the jars into the ster- 
 ilizer, placing a piece of 
 wire screening or other false 
 bottom in the bottom of the 
 boiler. 
 
 5. isienUzing in a wash 
 boiler. — Pour in a few inches 
 of hot water around the jars. 
 Apply the cover of the 
 boiler. Unless the cover fits 
 very well place a cloth be- 
 neath it. Heat until steam 
 comes from beneath the 
 cover and then for the time 
 specified in table 1, page 36. 
 
 6. Bemoval from the boiler. 
 — Eemove immediately. Han- 
 dles on the wire screen 
 bottom or wire baskets to 
 hold the jars facilitate re- 
 moval. A cloth or a wire 
 jar lifter may be used. The 
 lifter in the illustration 
 serves well for lifting jars 
 and as a false bottom. Place 
 hot jars on wood or paper to 
 avoid cracking. 
 
 7. Tightening the covers. 
 — Tighten the covers imme- 
 diately and stand the jars 
 upside down. This insures 
 the sterilization of the cov- 
 ers. Leaky jars can be de- 
 tected by air bubbles enter- 
 ing during cooling. 
 
 Fig. 10. — Sterilizing and sealing jars of fruit. 
 
26 UNIVERSITY OF CALIFORNIA — EXPERIMENT STATION 
 
 Grape Fruit (Pomelo).— Grape fruit is now canned in large quan- 
 tities in Porto Rico and Florida and the industry is well established 
 in California. Use only thoroughly ripened fruit. Peel. Separate 
 the segments and peel these. Pack the peeled segments into jars or 
 cans. Add a boiling hot syrup of 50° Balling. Grape fruit may 
 also be canned in slices or cubes. See table 1 for sterilization. 
 
 Jelly Juices. — Boil jelly fruits as for jelly making. Thus, berries 
 and currants are crushed, boiled 5 minutes and without addition of 
 water; apples are sliced without previously peeling; enough water 
 is added to prevent scorching and the fruit is boiled until soft, usuall}^ 
 15-20 minutes. Press the boiled fruits and strain the juice. Heat 
 juice to boiling; pack into scalded jars and sterilize as directed in 
 table 1. Cans are not recommended for jelly juices. 
 
 Crown capped bottles may be used instead of jars if desired. (See 
 Circular 220.) 
 
 To use the jelly juice at a later date simply drain the juice care- 
 fully from the sediment in the jar — add the customary amount of 
 sugar and boil until the jelling point is reached. 
 
 Ripe Olives. — Two Lye Process. — The Mission variety is best for 
 home pickling, although the Manzanillo variety is also fairly satis- 
 factory. The Sevillano and Ascolano varieties are very difficult to 
 pickle and should not be used by those unfamiliar with the pickling 
 of ripe olives. 
 
 Harvesting. — Pick the olives after they have acquired a light pink 
 to red color and, if possible, before they have become jet black and 
 over-ripe. Avoid bruising and prolonged storage in boxes before 
 pickling. 
 
 Holding Solution. — If for any reason, it is necessary to ship the 
 olives a great distance or to store them for a week or longer before 
 pickling, cover them in suitable containers with a 5 per cent salt 
 solution (about 4 pounds of salt per 10 gallons) for three or four 
 days. Then cover them with a brine of about 12 per cent salt (about 
 9 pounds salt per 10 gallons of water) and keep the olives submerged 
 in this solution until used. However, in home canning the olives will 
 usually be pickled direct from the tree. 
 
 First Lye. — Prepare a lye solution of about I14 to II/2 per cent; 
 this is approximately II/2 to 2 ounces of granulated lye per gallon of 
 water, or approximately I/2 to % pound per 5 gallons of water. If 
 the olives are tender use not more than 1 ounce of lye per gallon of 
 water. 
 
Circular 276] HOME CANNING 27 
 
 Cover the olives in a stoneware jar or wooden container with this 
 lye solution. Stir every half hour and carefully observe the progress 
 of the lye. The color of the skins will change as the lye penetrates the 
 olives. Cut two or three olives lengthwise occasionally and when it is 
 observed that the lye has penetrated through the skins of practically 
 all of the olives and a short distance (%4-%2 inch) into the flesh of 
 some of them, remove and discard the lye solution. With lye at 
 60-65° F. the time required is usually four to six hours. With tender 
 skinned olives or at higher temperatures less time and with tough 
 skinned olives and lower temperatures more time may be required. 
 
 First Exposure to Air. — Leave the olives in the jar or tub and stir 
 three times daily to facilitate darkening of the color by oxidation. 
 In order to avoid bruising, large tubs of olives may be filled with 
 water at the time of stirring and the water draAvn off after stirring. 
 In small containers the fruit may be stirred with the hands without 
 adding water. 
 
 Normally four to five days' exposure to air is required to give the 
 desired color. 
 
 Second Lye. — The first lye treatment is to facilitate darkening of 
 the color. The second is to remove bitterness. 
 
 Prepare a solution of one ounce of lye per gallon of water and 
 place it on the olives. Stir them occasionally (about once an hour). 
 
 Cut two or three olives occasionally and carefully observe the 
 lye action ; it causes the flesh to darken slightly in color. Or obtain 
 from the druggist a small bottle of Plienolplitlialein solution. A drop 
 of this solution applied to the cut surface will develop a red color 
 to the depth of the lye penetration. If this solution is used, rinse the 
 lye from the olive in water before cutting it for the test. 
 
 Leave olives in the lye solution until it completely reaches the 
 pits of the fruit (usually 8-16 hours at 60-65° F.). 
 
 Water Treatment to Remove Lye. — When the lye has reached the 
 pits of the olives remove and discard it. Cover the olives with water 
 and leave them submerged in the water. 
 
 Change the water three times daily until all taste of lye is removed 
 or until the cut surface will no longer cause the test solution 
 (Phenolphthalein) to turn red or pink. Normally, seven days soaking 
 in water is required. 
 
 Curing in Brine. — The olives at this stage are edible, but require 
 salt to ''bring out" their flavor. Store the olives for three days in 
 a brine of about 4 ounces (^/4 pound) of salt per gallon of water. 
 They are then ready for serving or canning. 
 
28 UNIVERSITY OF CALIFORNIA EXPERIMENT STATION 
 
 Canning and Sterilizing. — Pack into cans or jars. Add boiling 
 hot brine of 4 ounces (i/4 pound) of salt per gallon. Seal cans. Place 
 scalded rubbers and caps on jars. 
 
 Sterilize as directed for vegetables in a pressure cooker at 240° F. 
 for 40 minutes (10 pounds steam pressure). 
 
 THE STATE BOAPvD OF HEALTH Hx\S RULED THAT ALL 
 OLIVES OFFERED FOR SALE MUST BE STERILIZED IN 
 THIS MANNER. 
 
 One Lye Process. — The preceding process produces olives of dark 
 color. If this color is not desired a lighter colored product of superior 
 flavor may be prepared by a single treatment. 
 
 In using this process cover the olives with a lye solution of 2 per 
 cent (2^/^ ounces of lye per gallon of water) and allow it to stand 
 with occasional stirring until the lye penetrates completely to the pit ; 
 normally 12 to 24 hours. 
 
 Remove the lye. Cover the olives with water. Change the water 
 three times daily until all taste of lye is removed (6-7 days). 
 
 Cure in brine, can and sterilize as directed for the two lye process. 
 
 D. SPECIAL DIRECTIONS FOR VEGETABLES 
 
 Most vegetables have only a small amount of acid as compared 
 with fruits. This low- degree of acidity, as we have seen, permits the 
 growth of certain bacteria which are very difficult to kill by heating. 
 Vegetables, therefore, are hard to sterilize. Tomatoes, which resemble 
 fruit in respect to their acidity, are an exception. 
 
 Usually in sterilizing vegetables temperatures above 212° F. are 
 necessary. This requires the use of tin cans and a steam-pressure 
 cooker. Steam-pressure cookers are not difficult to operate and can 
 be obtained at prices as low as $18.00. 
 
 Note. — Where a pressure sterilizer is not available, it is advised 
 that vegetables be dehydrated. A leaflet describing the construction 
 and operation of an inexpensive home size dehydrater for fruits and 
 vegetables is obtainable free of charge from the College of Agricul- 
 ture, Berkeley. 
 
 Artichokes. — Young artichokes only are used. The hard tip is 
 trimmed off and some of the outer bracts removed, leaving only the 
 tender parts. 
 
 They are blanched for 5 minutes in boiling water, acidified with 
 % measuring cup of lemon juice or vinegar per gallon, placed in 
 cans or jars and covered with hot 2 per cent brine. For sterilization 
 see table 2. 
 
Circular 276] 
 
 HOME CANNING 
 
 29 
 
 Asparagus. — Grade into larg-e, iiiediiiin, and small sizes. Cut into 
 lengths to fit the container. This is conveniently done by making a 
 small box, i/4 ^^^ch less than the depth of the can or jar and open at 
 the top and one side. The bud ends of the stalks are placed in the 
 box against the closed end and the butts protrude from the open end. 
 They ma}^ be cut off flush with the edges of the open side of the box 
 with a large sharp knife. 
 
 Blanch the stalks in boiling water for about 4 minutes. Pack into 
 jars or cans with the tips up. Fill with hot brine and seal. Sterilize 
 as directed in table 2. 
 
 Fig. 11. — Pressure sterilizer for home une. (Courtesy of the Heuuinger Ayes Co.) 
 
 Green Beans. — Green beans are best for canning when very young 
 and tender, the larger and harder the pods and beans become, the 
 lower their value for canning. Commercially, beans are usually put 
 up in No. 2 cans. 
 
 Snip or string after sorting. The larger sizes should be cut into 
 pieces about one and one-half inches long, while the small or No. 1 
 grade may be canned whole. 
 
30 UNIVERSITY OF CALIFORNIA EXPERIMENT STATION 
 
 Blanch the No. 1 grade two minutes in boiling water and the larger 
 grades for five minutes. Fill into cans hot. 
 
 Fill with hot brine and seal cans. Sterilize as directed in table 2. 
 
 Beets. — Beets should be small and turnip-shaped if canned for 
 market. The first grade may be 1 to l^/o inches in diameter and the 
 second over one and one-half inches. The large beets are quartered 
 after peeling. 
 
 Scald in boiling water or in steam until the skin will slip easily, 
 usually about fifteen minutes. Chill in cold water, peel, trim, and fill 
 into enamel lined cans. Fill with hot brine and seal. Sterilize as 
 directed in table 2. 
 
 Sweet Corn. — Only young tender ears of good varieties of sugar 
 corn should be used. The corn must be fresh if good results are to 
 be expected. The ears are husked, and the corn is cut from the cob. 
 A syrup of % pound (one measuring cup) of sugar and II/2 ounces 
 salt (4 level tablespoons) per gallon is made. The corn and a small 
 amount of syrup (enough to cover the corn) are mixed and heated 
 in a pot to boiling. The mixture is filled hot into cans, sealed and 
 sterilized as directed in table 2. Cool the cans after sterilizing. 
 
 Peas. — Picking and hulling peas by hand is a very slow process and 
 not to be recommended for commercial canning. Large canneries 
 do the hulling, grading, blanching, and filling of cans entirely by 
 machinery. It is feasible, however, to shell enough peas for canning 
 by hand for home use. Use only fresh, tender peas. 
 
 Place the shelled peas in a wire basket or in a clean cloth and 
 blanch in boiling water long enough to wringle the skin slightly. This 
 will usually be about one to four minutes, depending upon the size 
 and tenderness of the peas. 
 
 Fill into cans and fill with hot brine, consisting of 2 ounces (5 
 tablespoons) of salt and I/2 measuring cup of sugar per gallon and 
 seal cans. Sterilize as directed in table 2. 
 
 Peppers, Pimientos. — These vegetables are usually peeled by caus- 
 ing the skin to separate by roasting or by immersing in hot oil. They 
 can be peeled successfully by im^mersing from two to three minutes 
 in cottonseed oil heated to smoking. They are then chilled at once 
 in cold water and the skins come off easily from the large peppers and 
 pimientos. Small, pungent, tough-skinned Mexican peppers do not 
 yield so well to this treament. When peeled in this w^ay, the peppers 
 are obtained soft and pliable and can be folded into the cans after 
 removing stems and seed cores. The peppers or pimientos may also 
 be peeled by roasting in a gas flame or in a very hot oven until the 
 skin will separate. 
 
Circular 276] HOME CANNING 31 
 
 Pack the peeled product into cans. Fill with ])oilin<? water or 
 brine. Sterilize as directed in table 2. 
 
 Pumpkin. — Scrape out fibrous pulp and seeds and cut the flesh 
 and rind into strips. Boil in water until soft. Scrape the flesh from 
 the rind and press through a colander. Boil to desired consistency. 
 Pack hot into cans and seal. Sterilize as directed in table 2. 
 
 Tomatoes. — Tomatoes have a considerable amount of acid wliich 
 checks the growth of heat-resistant bacteria. They are, therefore, 
 easily sterilized at 212° F. and jars may be used satisfactorily. 
 
 For canning purposes, the variety used should be smooth and of 
 a deep red color. Corrugated tomatoes are too difficult to peel. The 
 Stone is an excellent canning variety. 
 
 Sort the tomatoes and reject those which are spoiled and under- 
 ripe. Place them in a blanching basket and immerse in boiling water 
 long enough to crack and loosen the skin. This will usually be about 
 one-half to one minute. Remove and chill in cold water. Slip off the 
 skins and remove the cores. Pack the tomatoes tightly into jars or 
 cans and fill with juice or heat to boiling in the juice obtained in coring 
 and pack tightly into c^ns or jars hot and seal. If packed cold in 
 cans, the filled cans should be heated in boiling water or live steam 
 for five minutes before sealing. Sterilize as dire<?ted in table 1. 
 
 If the tomatoes are packed without the addition of juice, the 
 product is known as ''solid pack;" if juice is added, as "standard 
 pack." 
 
 Tomatoes may be canned whole to be used for slicing for salads, 
 although they will soften somewhat. Select small tomatoes that will 
 go into the jars or cans. Cover with a hot tomato juice pressed from 
 crushed fresh tomatoes. Seal. Sterilize as directed in table 1. 
 
 Tomato Puree and Hot Sauce. — Tomato puree or sauce is very con- 
 venient for flavoring many dishes, such as stews, soups and macaroni. 
 Cook until soft. Rub through a fine screen to remove skins, seeds, 
 and fiber. Concentrate the puree to about one-half its original volume 
 by boiling. Pack boiling hot into cans or jars and seal cans. Sterilize 
 as directed in table 1. If a hot sauce is desired, add salt, chopped 
 onions, and hot peppers to taste to the tomatoes before cooking and 
 screening. 
 
 Sweet Potatoes.— Wash. Boil until the skins will slip easily. Peel 
 quickly and pack hot, filling the cans as tightly as possible. Seal. 
 Sterilize as directed in table 2. After removal from sterilizer cans 
 should be chilled at once in cold water. 
 
32 UNIVERSITY OF CALIFORNIA EXPERIMENT STATION 
 
 Spinach and Other Greens. — Can as soon after picking as possible. 
 Trim off stems and imperfect portions. Wash thoroughly to remove 
 sand, etc. Blanch 3 to 5 minutes in steam rather than in water. 
 Water dissolves valuable food material. Pack hot into cans. Fill 
 with hot brine and seal. Sterilize as directed in. table 2. 
 
 Okra (Gumbo). — This vegetable is grown frequently in the hot 
 sections of the state for flavoring soups, stews, and other dishes. The 
 pods resemble green peppers in appearance. 
 
 Use only the young, tender pods for canning. Remove stems. 
 Blanch 6 to 8 minutes in boiling water. Pack into cans with boiling 
 water. Sterilize as directed in table 2. 
 
 Concentrated Soup Mixtures. — Vegetables such as carrots, onions, 
 tomatoes, beans, etc., may be prepared as for vegetable soup and 
 canned. A recipe recommended by the United States Department 
 of Agriculture is as follows: 
 
 ''A good combination consists of 1 quart of screened concentrated 
 tomato pulp (boiled tomatoes screened and two volumes of pulp boiled 
 down to one volume), 1 pint of green corn or tiny Lima beans, 1 pint 
 of okra or sweet peppers, 1 small onion chopped, % cup of chopped 
 sweet red pepper, II/2 teaspoonfuls of salt, and 3 teaspoonfuls of 
 sugar. Cook the tomatoes, pepper, and onion; put through a sieve 
 to remove seeds ; and cook down to about the consistency of ketchup. 
 Measure, add the corn or beans and okra, which have been prepared 
 as for canning. Add the seasoning and cook all together for 10 min- 
 utes. Pack at once into hot jars, and process as directed in table 2. 
 Tin cans should be plunged immediately into cold water and cooled 
 as quickly as possible. When cool, store in a dark, dry, cool place." 
 
 If all of the vegetables recommended are not available, others may 
 be substituted, thus, cooked white beans for corn, pimientos for okra, 
 white potatoes for Lima beans. Celery makes a valuable addition to 
 the mixture. When used for soup the canned product is diluted with 
 water and flavored with bouillon cubes or meat broth. For con- 
 venience it should be put up in small cans. 
 
 E. SPECIAL DIRECTIONS FOR MEATS 
 
 Meats, owing to their texture and absence of acidity are even more 
 difficult to sterilize than vegetables. If incompletely sterilized, they 
 may be attacked by certain heat-resistant bacteria which produce 
 dangerous poisons. By carefully carrying out the directions given 
 in this circular, however, there is no danger from this source. 
 
Circular 270] HOME CANNING 33 
 
 For home canning, the meat should first be seasoned and partially 
 cooked. For example, chicken or rabbit may be fried a short time 
 before being placed in the cans and beef should be corned or cooked 
 in some suitable way before canning. 
 
 The meat should be placed in the containers as hot as possible, as 
 heat penetrates slowly during sterilization. The spaces between the 
 pieces of meat should be filled with hot liquid, such as a suitable sauce. 
 A hot, dilute gelatin solution is suitable, as it forms a stiff jelly be- 
 tween the pieces of meat. Any good brand of unflavored gelatine 
 will do. 
 
 After filling and before sealing and sterilizing, cans should be 
 exhausted in boiling water for 10 to 20 minutes before sealing. Jars 
 should not be used. 
 
 Meat requires 40 to 80 minutes at 15 pounds steam pressure. 
 
 Canned Boiled Beef. — Remove the bones and rub the pieces of 
 meat with a mixture of 5 parts of salt and 1 part of sugar. To im- 
 prove the color a very small amount of saltpetre may be mixed with 
 the salt. Repeat this rubbing 12 hours later. Tie the pieces together 
 with twine and place in a pot, covering with salted water. Simmer 
 for about two hours or until the meat is tender. Cooking before can- 
 ning is necessary to prevent shrinkage in volume in the can. The 
 flavor may be improved by placing a cotton bag containing a small 
 quantity of mixed spices in the liquid while cooking. A suitable 
 mixture is black pepper, 24 parts ; bay leaves, 8 parts ; mace, 6 parts ; 
 and nutmeg, 3 parts. A little vinegar may also be added. 
 
 When cooked, cut the meat into pieces of suitable size and fill the 
 cans and cover with hot meat bouillon. This bouillon is made by boil- 
 ing down the liquor in which the meat was cooked and adding a little 
 gelatine previously dissolved in water. Seal cans and sterilize as 
 directed in table 2. 
 
 Chicken and Rabbit.— Boil in lightly salted water until tender and 
 remove the bones. Pass through a meat chopper if desired. Mix the 
 prepared meat with a highly seasoned tomato sauce or with a white 
 sauce made of flour, water, and spice; or other suitable sauce, and 
 pack in cans or jars. Several ripe olives added to each can is an 
 improvement. 
 
 Heat cans for 20 minutes in boiling water, seal, and sterilize as 
 directed in table 2. 
 
 The meat may also be canned with the bones. It may be fried, 
 roasted, or boiled, cut into pieces of suitable size, and packed in cans 
 or jars in the liquid in which it is cooked, and sterilized as above. 
 
34 UNIVERSITY OF CALIFORNIA — EXPERIMENT STATION 
 
 It may also be placed in the cans raw and cooked and sterilized 
 at the same time, but when prepared in this way, is inferior in flavor 
 and appearance and shrinks greatly in volume. 
 
 Fish. — Small fish may be canned whole; large fish are cut into 
 pieces of convenient size. Cooking and sterilizing take place in the 
 can. 
 
 Large Fish. — After cleaning and cutting into pieces, the fish is 
 improved if sprinkled with salt and allowed to stand and drain for 
 a few hours. It is then washed, packed in cans, and covered with 
 brine. It is then heated in the open cans in boiling water or steam 
 for twenty minutes and the cans are sealed. 
 
 Small Fish. — The principal small fish canned is the sardine, though 
 other small fish, such as small trout, may be canned in a similar way. 
 
 They may be canned in a tomato catsup or a mustard and vinegar 
 sauce, flavored with spices. The heads of the fish are cut off, the scales 
 removed if necessary, and the fish cleaned. They are then cooked in 
 boiling water or steam, drained, and packed in cans. The hot sauce 
 is then poured over them and the cans sealed and sterilized. 
 
 They may also be canned in olive, cottonseed, or peanut oil. They 
 are, in this case, prepared as above, but are cooked in boiling oil 
 instead of steam. They are then packed in cans with the oil, sealed 
 and sterilized. Fish may be kippered before canning by smoking for 
 two to three hours in smoke from oak sawdust. If to be kippered, the 
 fish should be stored in brine (about 1/2 pound of salt per gallon) for 
 3-4 hours before smoking. 
 
 With tomato or vinegar sauces, heating for 40 minutes at 240° P. 
 is sufficient for sterilization. In oil or a sauce that is not acid, they 
 require heating to 250° F. or 15 pounds pressure for 75 minutes. 
 
 F. PTOMAIN AND BOTULINUS POISONING 
 
 If meat or vegetables are found after canning and storage to be 
 partially decomposed or ''soured," they may contain dangerous 
 poisons. 
 
 Ptomains. — Poisonous ptomains rarely occur in canned food. 
 They are produced by forms of protein-destroying bacteria, for 
 example, by Bacillus protend vidgaris, one of the commonest organisms 
 of spoiled meat. The presence of ptomains is usually accompanied by 
 a noticeable odor of decomposition. So far as is known, they do not 
 frequently occur in cannc^l fruits or vegetables. Ptomains are not 
 destroyed by heating, so that badly spoiled meat is not rendered 
 harmless b}^ canning or cooking. 
 
ClHCULAH 276J HOME (!ANNIN(; '55 
 
 Hokdinus Poisoning. — A more violent poison is produced hy 
 Bacillus hohdinns, a microorganism which may grow in meats, vege- 
 tables and fruits low in acid. This bacteria sometimes grows in cans 
 and jars of vegetables put up by the ordinary household method in 
 which the food is not sterilized in the jar, and deaths have occurred 
 froni the use of such canned vegetables in the uncooked state. It is 
 very dangerous to can such vegetables as peas, beans, or corn, simply 
 by cooking them until they are done and then sealing them in cans or 
 jars without further sterilization. The heat in this method is not 
 sufficient to kill the spores of the Bacillus botulinus which may develop 
 later and produce enough poison to be fatal. 
 
 The botulinus toxin is many times more poisonous than strychnine 
 and is very hard to detect ; the only outward evidence of its presence 
 being a more or less rancid odor and gas pressure. The poison is, how- 
 ever, destroyed by heating to the boiling point for a reasonably long 
 period (30 minutse). Therefore, if canned vegetables are thoroughly 
 cooked after opening, there is little danger of botulinus poisoning. 
 
 The botulinus bacteria will not grow readily in acid substances, 
 such as most fruits, rhubarb and tomatoes. The organism, however, 
 may grow in rare cases in fruits of low acidity, such as pears and 
 over-ripe apricots, etc. 
 
 Never Taste Spoiled Canned Food. — Suspicious jars or cans of 
 food, that is, those which possess a disagreeable odor or show gas 
 pressure, should be destroyed without tasting. The contents of such 
 jars should be mixed with several spoonfuls of lye and jar and con- 
 tents buried. Suspected material should be destroyed and not fed 
 to chickens or animals. Many cases are on record in which valuable 
 chickens have been killed by eating spoiled canned foods. Other cases 
 of fatal poisoning have resulted from merely tasting spoiled cans of 
 food. 
 
 If the methods recommended in this circular are carefully followed 
 there will be no danger from botulinus poisoning. 
 
 Pressure Sterilization of Vegetables Necessary. — Vegetables, except 
 rhubarb and tomatoes, must be sterilized under steam pressure as 
 directed in table 2 in order to be safe. Do not attempt to sterilize 
 such vegetables in boiling water or an open steam cooker only. This 
 circular supersedes Circular No. 158 and other publications in which 
 sterilizing in boiling water may be fou7id recommended. Disregard 
 the direction.'^ in these older publications. 
 
36 
 
 UNIVERSITY OF CALIFORNIA EXPERIMENT STATION 
 
 G. CONDENSED DIRECTIONS 
 
 Tables 1 and 2 give brief directions for preparation and safe 
 periods of sterilization for home canned products. 
 
 TABLE 1 
 
 Variety 
 
 Apples 
 
 Apricots 
 
 Berries, all varieties. 
 
 Cherries, sweet 
 
 Cherries, sour for pie. 
 Figs (preserved) 
 
 Figs in syrup 
 
 Grapes, Muscat. 
 
 Peaches, cling 
 
 Peaches, free. 
 Pears 
 
 Plums. 
 
 Prunes, fresh. 
 Rhubarb 
 
 Tomatoes 
 
 Tomato puree. 
 Jelly jviiees 
 
 Fruit juices. 
 
 Preparation 
 
 Peel, core, quarter, blanch 
 
 3-4 min. 
 Halve and pit; blanch in 
 
 medium syrup 3-4 min. 
 Boil 3 min. with equal 
 
 weight of sugar, stand 
 
 24 hours, pack hot. 
 Stem; pit if desired 
 
 Stem and pit 
 
 Equal parts sugar, fruit, 
 and water cooked to 
 preserves; can hot. 
 
 Sort and wash 
 
 Stem 
 
 Halves, pit and peel. 
 
 Halves, pit and peel.. 
 Peel, halve, and core.. 
 
 Sort, stem, and wash. 
 
 Halves, pit and peel 
 
 Wash, cut, and stew un- 
 til soft; pack hot; no 
 sugar. 
 
 Scald, cold, dip, peel, and 
 core. 
 
 Boil soft, screen, boil to 
 Yi volume and can hot. 
 
 Boil fruit; press and strain 
 juice as for jelly mak- 
 ing; can hot. 
 
 (See Circular 220) 
 
 Syrup * recommended 
 
 Water. 
 
 Medium or heavy; 40 or 
 
 60° Bal. 
 In own syrup 
 
 Medium or light; 40 or 20° 
 
 Water 
 
 In own syrup. 
 
 Very heavy; 70-75° Bal... 
 Medium or light; 40 or 
 
 20° Bal. 
 Medium or heavy; 40 or 
 
 60° Bal. 
 
 do 
 
 Medium or light; 40 or 
 
 20° Bal. 
 Heavy or medium; 00 or 
 
 40° Bal. 
 
 Medium; 40° Bal 
 
 In own juice 
 
 In own juice.. 
 In own juice.. 
 In own juice.. 
 
 Minutes steriliza- 
 tion in boiling 
 water or steam 
 at 212° F. 
 
 Quart 
 jars 
 
 120 
 20 
 
 35 
 
 20 
 
 Quart 
 cans 
 
 120 
 15 
 
 30 
 
 10 
 
 * Syrups: For convenienC3, syrups are classified as: Light, 1 cup of sugar to 4 
 1 cup of sugar to 2 of water, and heavy, 1 14, cups of sugar to 1 of water. 
 
 of water; Medium, 
 
Circular 276] 
 
 HOME CANNING 
 
 37 
 
 TABLE 2 
 
 Condensed Directions for Vegetables, Olives, and Meats 
 
 For brines see special directions for each product. Use only cans for products 
 listed in this table. 
 
 Variety 
 
 Preparation 
 
 Minutes sterilization 
 
 At 10 lbs. 
 pressure 
 
 At 15 lbs. 
 pressure 
 
 
 Blanch 5 minutes in water with % cup vinegar 
 per gal. 
 
 30 
 
 30 
 30 
 30 
 150 
 65 
 40 
 40 
 50 
 
 120 
 
 90 
 
 50 
 
 120 
 
 20 
 
 
 20 
 
 String beans 
 
 Snip, cut, and blanch 2-10 minutes 
 
 
 Beets 
 
 
 
 
 
 80 
 
 Greens and spinach 
 
 Trim, wash, blanch 5 minutes 
 
 60 
 
 
 
 Okra ("gumbo") 
 
 Cut; blanch 6—8 minutes 
 
 
 Pimientos and peppers... 
 
 Pumpkin and squash 
 
 Sweet potatoes 
 
 Roast in flame or oven or heat in hot oil; chill; . 
 
 peel and core. 
 Cut; remove seeds and "rag"; cook; scrape from 
 
 skin; pack without brine. 
 Cook; peel; pack solid without brine 
 
 
 90 
 75 
 
 Vegetable soup mixture.. 
 Meats and fish 
 
 
 
 Cook, pack in Uquid from cooking, heat in steam 
 20 minutes; seal. 
 
 75 
 
 
 
 Effect of Altitude. — The times given in Table 1 for sterilizing in 
 boiling water are designed for altitudes from sea level to 1,000 feet* 
 For altitudes above 1,000 feet the length of sterilization in boiling 
 water should be increased about 20 per cent (one-fifth) for each addi- 
 tional one thousand feet. Thus at 2,000 feet a sterilizing time of 60 
 minutes in boiling water would become 60 plus 12, or 72 minutes. 
 
 Sterilization under pressure is also affected by altitude ; therefore, 
 the pressure should be increased 1 pound for each 2,000 feet increase 
 in elevation. The pressures and times in the table apply from sea level 
 to about 2,000 feet. 
 
STATION PUBLICATIONS AVAILABLE FOR FREE DISTRIBUTION 
 
 BULLETINS 
 
 No. 
 253. 
 
 261. 
 
 262. 
 
 268. 
 268. 
 273. 
 
 275. 
 
 276. 
 277. 
 278. 
 279. 
 280. 
 
 283. 
 285. 
 286. 
 287. 
 294. 
 298. 
 804. 
 
 312. 
 317. 
 
 319. 
 321. 
 324. 
 
 325. 
 
 828. 
 331. 
 384. 
 
 335. 
 
 336. 
 
 339. 
 
 343. 
 344. 
 
 Irrigation and Soil Conditions in the 
 Sierra Nevada Foothills, California. 
 
 Melaxuma of the Walnut, "Juglans 
 regia." 
 
 Citrus Diseases of Florida and Cuba 
 Compared with those of California. 
 
 Size Grades for Ripe Olives. 
 
 Growing and Grafting Olive Seedlings. 
 
 Preliminary Report on Kearney Vine- 
 yard Experimental Drain. 
 
 The Cultivation of Belladonna in Cali- 
 fornia. 
 
 The Pomegranate. 
 
 Sudan Grass. 
 
 Grain Sorghums. 
 
 Irrigation of Rice in California. 
 
 Irrigation of Alfalfa in the Sacramento 
 Valley. 
 
 The Olive Insects of California. 
 
 The Milk Goat in California. 
 
 Commercial Fertilizers. 
 
 Vinegrar from Waste Fruits. 
 
 Bean Culture in California. 
 
 Seedless Raisin Grapes. 
 
 A Study of the Eflfects of Freezes on 
 Citrus in California. 
 
 Mariout Barley. 
 
 Selections of Stocks in Citrus Propa- 
 gation. 
 
 Caprifigs and Caprification. 
 
 Commercial Production of Grape Syrup. 
 
 Storage of Perishable Fruit at Freezing 
 Temperatures. 
 
 Rice Irrigation Measurements and Ex- 
 periments in Sacramento Valley, 
 1914-1919. 
 
 Prune Growing in California. 
 
 Phylloxera-Resistant Stocks. 
 
 Preliminary Volume Tables for Second- 
 Growth Redwood. 
 
 Cocoanut Meal as a Feed for Dairy 
 Cows and Other Livestock. 
 
 The Preparation of Nicotine Dust as 
 an Insecticide. 
 
 The Relative Cost of Making Logs from 
 Small and Large Timber. 
 
 Cheese Pests and Their Control. 
 
 Cold Storage as an Aid to the Market- 
 ing of Plums. 
 
 No. 
 
 346. 
 347. 
 
 348. 
 349. 
 
 350. 
 351. 
 352. 
 
 353. 
 354. 
 355. 
 357. 
 
 358. 
 
 359. 
 360. 
 
 361. 
 
 362. 
 363. 
 
 364. 
 
 866. 
 
 367. 
 
 368. 
 
 369. 
 370. 
 371. 
 
 372. 
 
 373. 
 374. 
 
 375. 
 376. 
 
 Almond Pollination. 
 
 The Control of Red Spiders in Decidu- 
 ous Orchards. 
 
 Pruning Young Olive Trees. 
 
 A Study of Sidedraft and Tractor 
 Hitches. 
 
 Agriculture in Cut-over Redwood Lands. 
 
 California State Dairy Cow Competition. 
 
 Further Experiments in Plum Pollina- 
 tion. 
 
 Bovine Infectious Abortion. 
 
 Results of Rice Experiments in 1922. 
 
 The Peach Twig Borer. 
 
 A Self-mixing Dusting Machine for 
 Applying Dry Insecticides and 
 Fungicides. 
 
 Black Measles, Water Berries, and 
 Related Vine Troubles. 
 
 Fruit Beverage Investigations. 
 
 Gum Diseases of Citrus Trees in Cali- 
 fornia. 
 
 Preliminary Yield Tables for Second 
 Growth Redwood. 
 
 Dust and the Tractor Engine. 
 
 The Pruning of Citrus Trees in Cali- 
 fornia. 
 
 Fungicidal Dusts for the Control of 
 Bunt. 
 
 Turkish Tobacco Culture, Curing and 
 Marketing. 
 
 Methods of Harvesting and Irrigation 
 in Relation to Mouldy Walnuts. 
 
 Bacterial Decomposition of Olives dur- 
 ing Pickling. 
 
 Comparison of Woods for Butter Boxes. 
 
 Browning of Yellow Newtown Apples. 
 
 The Relative Cost of Yarding Small 
 and Large Timber. 
 
 The Cost of Producing Market Milk and 
 Butterfat on 246 California Dairies. 
 
 Pear Pollination. 
 
 A Survey of Orchard Practices in the 
 Citrus Industry of Southern Cali- 
 fornia. 
 
 Results of Rice Experiments at Cor- 
 tena, 1923. 
 
 Sun-Drj^ing and Dehydration of Wal- 
 nuts. 
 
 CIRCULARS 
 
 No. No. 
 
 70, Observations on the Status of Corn 161. 
 
 Growing in California. 164. 
 
 Alfalfa. 165. 
 
 The Use of Lime and Gypsum on Cali- 
 fornia Soils. 166. 
 
 Correspondence Courses in Agriculture. i67. 
 
 117. The Selection and Cost of a Small 170! 
 Pumping Plant. 
 
 House Fumigation. 172. 
 
 The Control of Citrus Insects. 173. 
 
 Melilotus indica as a Green-Manure 
 
 Crop for California. 174. 
 
 Oidium or Powdery Mildew of the Vine. 178. 
 
 Feeding and Management of Hogs. 179. 
 
 Some Observations on the Bulk Hand- 
 ling of Grain in California. 184. 
 
 Announcement of the California State 190. 
 
 Dairy Cow Competition, 1916-18. 193. 
 
 Irrigation Practice in Growing Small 198. 
 
 Fruit in California. 199. 
 
 Bovine Tuberculosis. 201. 
 
 Control of the Pear Scab. 202. 
 
 Home and Farm Canning. 
 
 Lettuce Growing in California. 203. 
 
 87 
 111 
 
 113. 
 
 127. 
 129. 
 136. 
 
 144. 
 151. 
 152. 
 
 153. 
 
 154. 
 
 155. 
 157. 
 158. 
 160. 
 
 Potatoes in California. 
 
 Small Fruit Culture in California. 
 
 Fundamentals of Sugar Beet Culture 
 
 under California Conditions. 
 The County Farm Bureau. 
 Feeding Stuffs of Minor Importance. 
 Fertilizing California Soils for the 1918 
 
 Crop. 
 Wheat Culture. 
 The Construction of the Wood-Hoop 
 
 Silo. 
 Farm Drainage Methods. 
 The Packing of Apples in California. 
 Factors of Importance in Producing 
 
 Milk of Low Bacterial Count. 
 A Flock of Sheep on the Farm. 
 Agriculture Clubs in California. 
 A Study of Farm Labor in California. 
 Syrup from Sweet Sorerhum. 
 Onion Growing in California. 
 Helpful Hints to Hog Raisers. 
 County Organizations for Rural Fire 
 
 Control. 
 Peat as a Manure Substitute. 
 
OIROULiARS — OorUinued 
 
 No. 
 205. 
 
 206. 
 208. 
 
 209. 
 210. 
 212. 
 214. 
 
 215. 
 217. 
 
 219. 
 
 220. 
 228. 
 230. 
 
 231. 
 
 232. 
 
 233. 
 234. 
 
 235. 
 
 236. 
 
 237. 
 
 238. 
 239. 
 
 240. 
 
 241. 
 
 243. 
 
 244. 
 245. 
 
 Blackleg. 
 
 Jack Cheese. 
 
 Summary of the Annual Reports of the 
 Farm Advisors of California. 
 
 The Function of the Farm Bureau. 
 
 Suggestions to the Settler in California. 
 
 Salvaging Rain-Damaged Prunes. 
 
 Seed Treatment for the Prevention of 
 Cereal Smuts. 
 
 Feeding Dairy Cov^s in California. 
 
 Methods for Marketing Vegetables in 
 California. 
 
 The Present Status of Alkali. 
 
 Unfermented Fruit Juices. 
 
 Vineyard Irrigation in Arid Climates. 
 
 Testing Milk, Cream, and Skim Milk 
 for Butterfat. 
 
 The Home Vineyard. 
 
 Harvesting and Handling California 
 Cherries for Eastern Shipment. 
 
 Artificial Incubation. 
 
 Winter Injury to Young Walnut Trees 
 during 1921-22. 
 
 Soil Analysis and Soil and Plant Inter- 
 relations. 
 
 The Common Hawks and Owls of Cali- 
 fornia from the Standpoint of the 
 Rancher. 
 
 Directions for the Tanning and Dress- 
 ing of Furs. 
 
 The Apricot in California. 
 
 Harvesting and Handling Apricots and 
 Plums for Eastern Shipment. 
 
 Harvesting and Handling Pears for 
 Eastern Shipment. 
 
 Harvesting and Handling Peaches for 
 Eastern Shipment. 
 
 Marmalade Juice and Jelly Juice from 
 OitruB Fruits. 
 
 Central Wire Bracing for Fruit Trees. 
 
 Vine Pruning Systems. 
 
 No. 
 
 247. 
 248. 
 
 249. 
 250. 
 
 251. 
 
 252. 
 253. 
 254. 
 
 255. 
 
 256. 
 257. 
 258. 
 259. 
 260. 
 
 261. 
 262. 
 263. 
 264. 
 
 265. 
 266. 
 
 267. 
 
 268. 
 
 269. 
 270. 
 271. 
 
 272. 
 
 273. 
 
 275. 
 
 Colonization and Rural Development. 
 
 Some Common Errors in Vine Pruning* 
 and Their Remedies. 
 
 Replacing Missing Vines. 
 
 Measurement of Irrigation Water on 
 the Farm. 
 
 Recommendations Concerning the Com- 
 mon Diseases and Parasites of 
 Poultry in California. 
 
 Supports for Vines. 
 
 Vineyard Plans. 
 
 The Use of Artificial Light to Increase 
 Winter Egg Production. 
 
 Leguminous Plants as Organic Fertil 
 izer in California Agriculture. 
 
 The Control of Wild Morning Glory. 
 
 The Small-Seeded Horse Bean. 
 
 Thinning Deciduous Fruits. 
 
 Pear By-products. 
 
 A Selected List of References Relating 
 to Irrigation in California. 
 
 Sewing Grain Sacks. 
 
 Cabbage Growing in California. 
 
 Tomato Production in California. 
 
 Preliminary Essentials to Bovine Tuber- 
 culosis Control. 
 
 Plant Disease and Pest Control. 
 
 Analyzing the Citrus Orchard by Means 
 of Simple Tree Records. 
 
 The Tendency of Tractors to Rise in 
 Front; Causes and Remedies. 
 
 Inexpensive Labor-saving Poultry Ap- 
 pliances. 
 
 An Orchard Brush Burner. 
 
 A Farm Septic Tank, 
 
 Brooding Chicks Artificially. 
 
 California Farm Tenancy and Methods 
 of Leasing. 
 
 Saving the Gophered Citrus Tree. 
 
 Marketable California Decorative 
 Greens.