UNIVERSITY OF CALIFORNIA PUBLICATIONS COLLEGE OF AGRICULTURE AGRICULTURAL EXPERIMENT STATION BERKELEY, CALIFORNIA THE, CREAM SUPPLY By HERBERT A. HOPPER BULLETIN No. 209 (Berkeley, Cal., January, 1911) BERKELEY THE UNIVERSITY PRESS 1911 Benj. Ide Wheeler, Ph.D., LL.D., President of the University. EXPERIMENT STATION STAPE. E. J. Wickson, M.A., Director and Horticulturist. E. W. Hilgard, Ph.D., LL.D., Chemist (Emeritus). W. A. Setchell, Ph.D., Botanist. Elwood Mead, M.S., C.E., Irrigation Engineer. (Absent on leave.) Lerov Anderson, Ph.D., Dairy Industry and Superintendent University Farm Schools. M. E. Jaffa, M.S., Nutrition Expert, in charge of the Poultry Station. R. H. Loughridge, Ph.D., Soil Chemist and Physicist (Emeritus). C. W. Woodworth, M.S., Entomologist. Ralph E. Smith, B.S., Plant Pathologist and Superintendent of Southern California Patho- logical Laboratory and Experiment Station. G. W. Shaw, M.A., Ph.D., Experimental Agronomist and Agricultural Technologist, in charge of Cereal Stations. E. W. Major, B.Agr., Animal Industry, Farm Manager, University Farm, Davis. F. T. Bioletti, B.S., Viticulturist. George E. Colby, M.S., Chemist (Fruits, Waters and Insecticides), in charge of Chem. Lab. H. J. Quayle, A.B., Assistant Entomologist, Plant Disease Laboratory, Whittier. W. T. Clarke, B.S., Assistant Horticulturist and Superintendent of University Extension in Agriculture. H. M. Hall, Ph.D., Assistant Botanist. C. M. Haring, D.V.M., Assistant Veterinarian and Bacteriologist. John S. Burd, B.S., Chemist, in charge of Fertilizer Control. E. B. Babcock, B.S., Assistant Agricultural Education. H. A. Hopper, M.S. A., Dairy Industry, University Farm, Davis. W. B. Herms, M.A., Assistant Entomologist. J. H. Norton, M.S., Assistant Chemist, in charge of Citrus Experiment Station, Riverside. W. T. Horne, B.S., Assistant Plant Pathologist. J. E. Coit, Ph.D., Assistant Pomologist, Plant Disease Laboratory, Whittier. C. B. Lipman, Ph.D., Assistant in Soil Bacteriology. R. E. Mansell, Assistant in Horticulture, in charge of Central Station grounds. A. J. Gaumnitz, M.S., Assistant in Cereal Investigations, University Farm, Davis. E. H. Hagemann, Assistant in Dairying, Davis. B. S. Brown, B.S.A., Assistant in Horticulture, University Farm, Davis. F. D. Hawk, # B.S.A., Assistant in Animal Industry. J. I. Thompson; B.S., Assistant in Animal Industry, Davis. R. M. Roberts, B.S.A., Field Assistant in Viticulture, University Farm, Davis. J. C. Bridwell, B.S., Assistant Entomologist. C. H. McCharles, B.S., Assistant in Agricultural Chemical Laboratory. J. C. Roper, Patron University Forestry Station, Chico. Mrs. D. L. Bunnell, Secretary to the Director. E. C. Miller, Foreman University Forestry Station, Chico. N. D. Ingham, B.S., Assistant in Sylviculture, Santa Monica. John T. Bearss, Foreman Kearney Park Station, Fresno. E. H. Smith, M.S., Assistant Plant Pathologist. T. F. Hunt, B.S'., Assistant Plant Pathologist, C. O. Smith, M.S., Assistant Plant Pathologist, Plant Disease Laboratory, Whittier. M. E. Stover, B.S., Assistant in Agricultural Chemical Laboratory. P. L. MoCreary, B.S., Laboratory Assistant in Fertilizer Control. F. L. Yeaw, B.S., Assistant Plant Pathologist, Vacaville. F. E. Johnson, B.L., M.S., Assistant in Soil Laboratory. CHARLES Fuchs, Curator Entomological Museum. P. L. HlBBARD, B.S., Assistant Fertilizer Control Laboratory. W. H. VOLCK, Field Assistant in Entomology, Watsonville. E. I,. MORRIS, B.S., Field Assistant in Entomology, San Jose. J. S. HUNTER, Field Assistant in Entomology, San Mateo. L. M. Davis, B.S., Assistant in Dairy Husbandry, University Farm, Davis. I. Bonnet, Assistant in Viticulture. S. S. ROGERS, B.S., Assistant Plant Pathologist, Plant Disease Laboratory, Whittier. B. A. Madson, U.S.A., Assistant in Cereal Laboratory. Walter E. Packard, M.S., Field Assistant [mperial Valley Investigation, El Centre E. E. Thomas. B.S., Assistant Chemist, Plant Disease Laboratory, Whittier. THE CREAM SUPPLY By HERBERT A. HOPPER. The present phenomenal growth of dairying in California calls specific attention to the necessity for a more general understanding among cream producers of certain well recognized factors and con- ditions, the improper control of which may unnecessarily increase butterfat losses on the farm or reduce the quality of the butter made from farm skimmed cream. Much depends upon the care the cream receives, and too great effort cannot be exerted through encouraging both higher sanitary and higher economic standards on the majority of California dairy farms. So far, unfortunately, little systematic effort has been made along these lines. It might at first seem that the logical way to reach the cream producer is through the creamery. As yet, however, most creameries have not made sufficient difference in the prices paid for different grades of cream to command the respect of the producer for any suggestions they might make looking to an improved quality. Then, too, the idea of doing things extensively has very generally concealed the ultimate significance of trifling daily losses. In spite of these conditions, the improvement of the general cream supply, and the checking of butterfat losses on the farm rests in a large measure with the creamery, and its cream solicitors. The redemption of quality demands a united effort. Some of the sanitary and economic features of the cream supply are discussed in the following pages with the purpose of pointing the way to higher quality and greater profits. SOURCES OF BACTERIA IN MILK. While milk as secreted in the udder is probably sterile, it has been repeatedly shown impossible, except in rare instances, to obtain milk from the cow 's udder that is not more or less contaminated with bacteria. They find their way readily into the inner parts of the udder through the milk duct and, flourishing in the presence of favor- able temperature and food, they are washed out by the process of 116 UNIVERSITY OF CALIFORNIA — EXPERIMENT STATION. An open sanitary milking stable suitable for certain parts of California. __- ' \. Bi'iirry t v ^ l An excellent type of shed to give the herd the necessary protection from sun in summer and rain in winter. Such a shed should be found on every dairy farm. Exposure to storm cuts down production. Bulletin 209. THE CREAM SUPPLY. 117 milking. Any disease of the udder may also add to the numbers of bacteria in the milk. The most abundant contamination usually comes after the milk has left the udder. Dirt or dust from the cow, hands of milker, utensils, or the dust of the stable, may add large numbers of bacteria. Strainers, coolers, bottles, and other apparatus, if unclean, may like- wise prove detrimental. In ways too numerous to mention, the process of contamination may go on. Not all bacteria are harmful. Some are helpful when they can be controlled, and others seem to be without detrimental properties. CAEE OF THE COW. From the sanitary viewpoint, it is more essential to groom the cows than the horses. Repeated trials show that where good stable conditions obtain from day to day, it requires not more than one minute to properly brush the flanks and sponge and dry the udder of a cow preparatory to milking. The body of the cow, and especially the flank and udder parts, must be clean and free from dust to insure good milk. Bacteria are transported upon dust particles. Don't groom the cows or distribute dusty foods or litter just before milking time. Always allow sufficient time for the dust to settle. It is cus- tomary to reject the first few streams of milk in first-class dairies, as such milk is of poor quality and likely to be highly contaminated with bacteria which have found entrance from the outside. It is little short of a crime to proceed to milk a filthy cow without first rendering her parts clean by scrubbing. The wise dairyman will maintain healthy surroundings for his herd at all times. The losses consequent upon neglect of this kind are too serious to be lightly considered. Only healthy cows will make the best use of their food, and the fact that they are perhaps unsound raises a grave question as to the wholesomeness of their milk. The consumer is coming to have little interest in questionable milk, except to avoid it. THE STABLE. The dairy stable must always be substantial and well built, but in most parts of California it will serve its purpose as well if of inex- pensive design. Light, ventilation, and ease of cleaning, are the main considerations. Fortunately, these can be accomplished at a much less expense than is usually believed. Concrete floors, gutters and mangers are recognized as essential to a well ordered dairy stable. They not only assist in securing sanitary conditions, but make it 118 UNIVERSITY OF CALIFORNIA EXPERIMENT STATION. A clean, well drained cow yard — essential to a properly kept dairy. ■J * wk * IS 1 11 Hi' "^^m *"■ FT .;:''* : *;''jC' wg^^inm^ Barn of a careless, thriftless, dairyman. Fertility is wasted and the milk contaminated. Bulletin 209. THE C REAM SUPPLY. 119 possible to properly save all the fertility in the manure, as well as contribute to the health and comfort of the cows. Where cows are to occupy the stable for any prolonged period, the usual rigid stanchion should give place to the modern swing stanchion, either of wood or wood and angle iron ; both of which are sanitary and convenient. The overhead litter carriers, as well as the patent mangers and watering devices, are convenient and paying in- vestments but are not absolutely necessary where the capital is limited. A definite system of ventilation is hardly necessary in this state, but light should be provided at the rate of four square feet of glass, or its equivalent, per cow. It is unreasonable to assume that a large herd will not contain occasionally an ailing cow so that the use of disin- fectants in the stable at frequent intervals is desirable. The periodic use of whitewash is essential as a disinfectant, and to present a cleanly appearance throughout the stable. The stable routine should be so planned as to have all operations that tend to raise a dust take place after milking. THE COW YAED. Under usual California conditions, the cow yard is a serious handi- cap to good dairy products. In summer it is so dusty that, whether the cows are milked in it, or the stable, the milk is greatly contam- inated thereby. In winter it becomes so muddy through constant rains that it is unfit for use except to further contaminate the milk. The stable should be set well up on a firm foundation so that the yard slopes away gently in all directions. The use of gravel is to be recommended. Some have employed concrete to conserve the manure and make sure that the cows are kept free from mud and filth. The manure should be removed from the stable daily and all parts of the yard cleaned every few days. This reduces the number of flies and the contamination of the milk. The practice of "milking in the corral" is possibly doing more to retard sanitary dairy progress in California than any other custom. Where the milk from such dairies goes to cheese factories, it produces a gassy curd and a low grade cheese ; when used for market purposes, it either fails to keep or may be the cause of digestive disorders in the consumer. A specific legislative act preventing such practices would do much to improve the condition of the milk. 120 UNIVERSITY OF CALIFORNIA EXPERIMENT STATION. Test tubes containing the actual amount of dirt or manure that would fall into the open pail from forty cows if milked while their udders were in the condition indicated. A clean cow and a clean milker — essential to pure milk or high-grade butter. The big problem before California dairymen to-day. Bulletin 209. THE cream SUPPLY. 121 THE MILKER. In some ways the quality of the milk is dependent to a very great extent upon the milker. His personal habits are everything in deter- mining the cleanliness of the product. He should be personally clean — have cleanly habits and enjoy perfect health. At no form of farm work does health count for so much. Unless the regular clothing is above suspicion, it will pay to furnish each milker with a frequently laundered outer garment, to be worn only at milking time. Milking with dry clean hands is essential. A properly equipped wash room is an inexpensive but paying accessory to the stable, as the milkers' hands will require an occasional washing, even under the best of con- ditions. The practice of wetting the hands in the milk is the most repulsive and should disqualify any milker where the owner has any regard for his business. Much is gained by milking in a quiet manner, both as to cleanliness and the amount and quality secured. MILKING MACHINES. The process of machine milking is as yet in a state of incomplete development, but enough studies have been made to throw some light upon the relation between machine milking and the keeping properties of the milk. There is such a lack of uniformity of conclusion as to their economic advantages that this phase will be passed over. Suf- ficient to say that many report them a paying investment and that their more general use in the future will be almost a necessity, if present tendencies prevail. Any device for milking cows that offers further means of contam- inating the milk has little chance to survive. At present, there is an abundance of rubber tubing and numerous intricate devices that are more or less difficult to clean. Nevertheless, with reasonable care these devices need not be the cause of further contamination, as it has been shown that they may be kept in order. In the hands of a careful operator, the quality of milk drawn by a modern machine will show less bacteria than most milk drawn in the ordinary manner. Careful trials have been made to sustain this conclusion. The protection of the milk from exposure in the stable, which the machine offers, is a great item if the interior surface of the apparatus is clean. All rules for care, operation, and washing of a milking machine must be relig- iouslv followed. 122 UNIVERSITY OF CALIFORNIA EXPERIMENT STATION. The ' ' Trueman ' ' sanitary milk pail. The compulsory use of a simple, practical sanitary pail like this by California dairymen would accomplish great good. "Trueman" pail inverted for steaming. Bulletin 209. THE C REAM SUPPLY. 123 UTENSILS. The use of sound utensils free from rust and in a cleanly condition, is essential to good milk. Battered or dented pails, cans, etc., and seams that are not flushed with solder cannot be readily cleaned by reasonable care in washing. Such uneven surfaces invite contamina- tion that is readily imparted to the milk, though the latter is sub- jected to it only momentarily. Such utensils are employed at a loss. New pails and cans may cause an immediate improvement in the pro- duct. Eusty cans are not only unsanitary, but the raw iron is shown to be slightly dissolved so that in such milk the action of rennet is hindered. An essential requirement in any utensil for handling milk is simplicity to which should be added durability. SANITARY MILK PAILS. Nothing will contribute so much to the cause of better milk as will the sanitary milk pail. The critical period in the life of milk is during the time of milking. Few who have not made careful tests, realize to what extent the wide-open pail invites dirt as compared with one wholly or partly covered. There should be greater interest in covered pails and dairy operators should have them used for the good it will do their business. Realizing that the dust particles are the carriers of the infection, the advantages of excluding dust are obvious. There are several styles of pails that are efficient in excluding the dust and falling dirt, but some are rather too complicated for general introduction. We call attention here to the Trueman pail (shown in cut) which answers all practical sanitary requirements and the use of which will not be resented by milkers. There are no detach- able parts to become foul and the opening permits of easy cleaning. This can be made from an ordinary pail by addition of the visor. The effect of the covered pail in excluding dirt, or what is equiva- lent, bacteria, may be seen in the following table showing figures from three different farms. Table I. Bacteria Per Cubic Centimeter. Stable Condtions. Fair Above average Poor Open pail 42,400 33,150 3,439,200 Covered pail 6,430 1,740 103,600 ; 'The use of the covered pail is of great advantage in any stable in excluding dirt and bacteria from the milk. The relative advantage gained by the use of the cover depends upon the sanitary conditions 124 UNIVERSITY OF CALIFORNIA — EXPERIMENT STATION. of the stable." When a strainer of any kind is used and it holds the dirt to be driven throngh later, it is of no advantage and may increase the germ content. The merits of the covered pail should appeal to California milk producers. WASH BOOMS. Using an original can of warm water to rinse a dozen dirty ones should in no wise be considered as in any way meeting the require- ments of washing. An appropriate room with means for obtaining hot and cold water with wash sink, draining rack, and steam jet for sterilizing are the least that can be expected in the way of washing- equipment. This room may or may not be separate from the separ- ator and milk handling room. It will be better if separate, and if milk is bottled and handled in any quantity the wash room should by all means be entirely by itself. The separator, bottling apparatus and refrigeration facilities should be at least grouped by themselves in one room, while the washing should be associated with the power plant, if there is one. Nothing short of a good cement floor meets the needs of a wash room or a dairy house in view of its lasting properties, comparatively low expense and greater sanitation. The side walls of the milk house should be tight, and there should be an abundance of light provided for. Windows and doors should be screened summer and winter, and milk or cream vats provided with cheesecloth or wire gauze screens to protect contents from such flies as gain entrance to the room. Where one is working for a reputation for his products, the importance of these precautions is paramount. WASHING. Washing dairy utensils is an important operation, though it in- volves but a few simple considerations. Always use a brush; never nse a cloth, as the latter cannot be kept in a sanitary condition. First rinse the utensil in cold or hike warm water — never hot water — as the latter tends to cook the milk fast to the tin. In this way, the bulk of the adhering milk is removed. Then water should be used containing sal soda or washing powder, but under no circumstances should soaps be used. In cleaning cans, the standard brush is very effective as it gets into the crevices and beneath the shoulder of the can more readily than anything else. Pails, dippers, etc., should re- ceive the same treatment. Thorough rinsing, after scrubbing in hot water and washing powder, is essential, after which steaming should take place over a steam jet or in an oven or chamber constructed for Bulletin 209. THE CREAM SUPPLY. 125 the purpose. After being steamed, the different pieces should never be touched with a cloth, but allowed to dry of their own heat. This prevents rust. Exposure to sunlight is desirable if same can be ac- complished away from the dust. By all means avoid the dust. THE MILK. Eecognizing the fact that the time of milking is the critical period in the life of milk or cream and that the covered pail and cleanly habits of milking are important to consider as influencing the keeping properties of milk, it is always desirable to remove the milk from the stable to the milk room as soon as practical and convenient. This con- tributes to its length of life. Open cans or pails of milk should never be allowed to stand unprotected in the stable. Either a few pails with covers, or a larger can should be in use to receive the milk from the milkers and be transported directly to the milk room at frequent inter- vals. It is better if the milk is poured from the milk pail, not in too close proximity to the cows. In a large dairy one person can take care of the milk from several milkers without their leaving the stable. In some dairies the milkers pass to a convenient room at the side or end of the stable where the milk is placed in cans for prompt removal, or perhaps it is strained into a conductor which conveys it by gravity to the receiving tank in the milk room. Circumstances must deter- mine the best method to follow. Any- system that succeeds in getting the milk promptly from the cow to the milk room without contami- nation is good, providing it is accomplished with a minimum amount of labor. COOLING. All milk or cream should be subjected to prompt cooling. From an elevated receiving tank or vat it can be led directly over any of the approved standard milk coolers. These are of different design and permit of the milk or cream passing in a very thin layer over a more or less extensive surface, the inside of which is generally cooled by the circulation of cold water. This process, if rightly carried on, may ac- complish two things — the rapid cooling of the milk, and the elimina- tion of odors therefrom. The aerating effect is in less favor in recent years than formerly, as it is easily seen that milk which is properly drawn from clean cows should have no * ' cowy ' ' odor, and that if good milk happened to be exposed in cooling to an impure atmosphere it might be injured rather than improved. The importance of cooling is obvious, but the air of the room where it is done must be pure. Clean milk may be put directly into bottles, sealed and cooled without 126 UNIVERSITY OF CALIFORNIA EXPERIMENT STATION. A suggestion for cooling and holding separator cream that can be made use of on any dairy farm in the absence of artificial means of cooling. Methods of insulating cans for delivering cream in hot weather. Right hand — felt cover; middle — wet burlap cover. Either is far superior to the naked can. Bulletin 209. THE C REAM SUPPLY. 127 any ill results from lack of aeration, showing that with proper cooling, milk that is good at the outset will keep in perfect condition as long as necessary. Where milk or cream is held in bulk for subsequent delivery, the cans should be emersed in cold water with a temperature, if possible, as low as 50° F. In many parts of California the well water is much warmer than this, and ice is out of the question. In the interior parts of the state, water from deep wells will average 70° F during the summer months, so that it has little to offer in the way of holding milk. In fact, under these circumstances, milk cannot be held with any de- gree of safety longer than is needed for its prompt delivery. Under such conditions we find that where it is necessary to handle and hold milk for shipment, artificial means of refrigeration are resorted to. In many parts of the state cold water is available in abundance. The water for stock may be passed through a convenient tank in which the cans of milk are emersed, and still be useful. In this way the milk gets the benefit of the original cooling and the water serves two pur- poses. A small tank for this purpose is shown in the accompanying cut. The inflow should deliver near the bottom, and the outtake at a safe distance from the top of the cans. By using this device in warm weather with water at 70°, it was possible to secure the following re- sults. While this is not enough cooling for milk, it would help very much in holding heavy farm skimmed cream and is given to show what might be done where cool water is available. Table II. Effic iency of Water Cooler. Eate of inflow, 75 gallons per hour. Periods h hour 1 hour 1| hours 2 hours 2| hoi Temperature, air 89 89 89 88 88 Temperature, water 70 70 70 70 70 Temperature, Milk 96 83 77 75 74 Milk, untreated 100 100 98 97 95 Milk was heated to 100° F. PROTECTION IN HAULING. The hauling of milk and especially cream for long distances is a necessary condition imposed upon dairymen in most parts of Cali- fornia. For a large part of the year, temperature conditions are un- favorable and some means of protection from the hot sun is absolutely necessary. The wagon should have either a cover of its own or the cans should be protected by a canvas cover over all. The latter practice is the more common, and the better method if both cannot be used, as 110° 104° 70 73 68 70 92 96 128 UNIVERSITY OF CALIFORNIA EXPERIMENT STATION. it is more helpful in keeping out the dust and probably offers as much protection as the other to the contents of the cans. In spite of its use, the high temperatures often seriously affect the milk or cream, and some means of additional protection are necessary. Accordingly, cer- tain forms of insulation for the cans have been devised to protect from the heat. The felt can covers have not as yet been used to the extent that they evidently should be. Wet burlap wrapped about a can has considerable merit as a means of keeping the contents cool. To test the efficiency of the two methods under identical conditions the following figures were tabulated : Table III. Effect of Insulating 10 Gal. Cans in Different Ways. Milk kept in the Shade Milk kept in the Sun Periods Start 1 hr. 3 hrs. 5 hrs. Start ] hr. 3 hrs. 5 hrs. Temperature of Air 9!)° 100° 99° 98° 114° 128° Temperature of f Dry felt cover 60 62 65 66 60 65 contents of \ Wet burlap cov.er 60 62 66 67 60 64 can ( No cover 60 61 78 82 60 80 The figures shown indicate the marked value of either method in keeping milk or cream in good condition. Considerable would be gained if after using the wet burlap or the dry felt cover, the hauling were done in a covered wagon. Keeping in the shade made a differ- ence of from 3 to 7 degrees. THE CREAM SEPARATOR. All that has been said thus far as pertaining to the improvement of the milk supply applies with just as much force to the production of wholesome cream. While the cream represents only a small portion of the original milk, it has a comparatively high commercial value and any unfavorable influence incident to the production of the milk is likely to be detected in the cream. On most dairy farms the cleanliness of the separator needs first attention. Like any other piece of apparatus for handling milk or cream, it must be kept scrupulously clean. The disastrous effects of using a foul separator bowl can be imagined only when recalling that all cream passing through it becomes seeded with the bacteria it con- tains. Unless the cream is held at very low temperatures, these are sure to develop bad flavors that are ultimately carried over into the butter which must consequently sell for less than otherwise. This one cause of bad flavors alone levies a heavy annual toll upon California creamery products, that could as well be saved. The bowl must be taken apart and washed each time it is used, following directions previously given for washing utensils. This is imperative nol only for sanitary but for economic reasons, as will be pointed out later. Bulletin 209. THE C REAM SUPPLY. 129 LOCATION OF SEPARATOR. When a separate milk house is available, the separator should be found there and never operated in the stable or in any place where the air is impure or the surroundings bad. We have seen many farm separators placed in filthy out-buildings or even out-of-doors where they serve as lodging places for the poultry of the farm at times when the machine is not in use. Nothing could be more antagonistic to quality. In fact such conditions are contrary to law, placing the owner liable to prosecution. A simple clean room with solid floor and screened windows and doors can be made to answer very well as a place to separate the cream. The initial cost of a good machine is enough to emphasize the need of protecting it from the weather. OPEEATION OF THE SEPARATOR. Each machine is usually accompanied by specific directions for setting up and operating. These should be carefully followed. As- suming that all the parts are properly adjusted, the first requirement is a firm foundation. W T ith care, most hand sizes can be set upon a solid wooden floor so as to run satisfactorily. Unless it is a firm floor without vibration, it will not do. A concrete pier with bolts imbedded for attaching 2-inch by 4-inch or 4-inch by 4-inch pieces to which the separator may be lagged, is the best. All vibration is thus avoided. Pieces of 2-inch by 4-inch bolted to a cement floor may be made to serve as well. Care must always be observed to set the frame per- fectly level, as otherwise the bowl will not run true. Placing a machine upon skids to be moved about the farm is a questionable practice, to say the least. The life of a standard separator depends upon its care to a great extent. One that is allowed to become gummy or dirty may wear out in a year. Keep it free from dirt and well oiled. Follow directions as to number of turns of crank per minute, as a uniform pull and not a series of jerks, will contribute to skimming efficiency and the life of the separator. The continued use of a light grade of oil such as is supplied with the machine should be followed, as .heavy oil gums the parts. An occasional run on coal oil is said to clean the bearings from gum and grit. An oil cloth or canvas cover for the machine when not in use, is quite worth the while in keeping dust and sand out of the bearings. 130 UNIVERSITY OF CALIFORNIA EXPERIMENT STATION. VARIATIONS IN CREAM TESTS. We often receive requests from patrons to explain the variation in cream tests from one delivery to the next. A farmer is likely to feel that when the milk is from the same herd, fed and milked in the same manner and the cream separated in the same way, that the per cent of fat in the cream should not vary. The fact is, a uniform test of farm separated cream is more indicative of dishonest testing than are variations of a few points between different deliveries. The aver- age cream patron is likely to look upon a sudden variation as incorrect. It is true that great care is needed to test cream accurately, even after the samples are properly taken, but variations are bound to occur that are entirely due to conditions under which the milk is separated. These conditions are such as affect the efficiency of skimming or the thickness of the cream. CAUSES OF VARIATION IN CREAM TESTS. These may be listed as follows: 1. Smooth running. 2. Speed. 3. Cleaning of the separator. 4. Rate of inflow. 5. Temperature of milk. 6. Condition of milk. 7. Richness of cream. 8. Richness of milk separated. 9. Amount of water or skim milk used in flushing the bowl. 1. Smooth Running. No machine will do good work when it does not run smoothly. Under such circumstances, the layers of the milk in the separator bowl, instead of arranging themselves in natural order, the cream in the center and the skim milk at the outside, are broken up and mixed by the vibration and much of the fat is likely to escape with the skim milk. If the bowl runs smoothly, the cream and skim milk are properly separated and find their respective outlets without inter- ference. In a series of trials where the machine was not level and the upper bearing loose, the average per cent, of butterfat lost in skim milk was Balanced, .03 per cent. Unbalanced, .17 Bulletin 209. THE cream SUPPLY. 131 2. Speed. The centrifugal force required to insure the efficient working of a separator of any kind depends upon the speed of the bowl. There is a certain speed at whioh every machine will do its best work. To attain this, a hand separator should be given as many revolutions of the crank per minute as is indicated on same. Usually a lower speed causes loss of butter fat in the skim milk, but a higher speed is without beneficial effects, and may prove injurious to the machine. With no change in the adjustment of the cream screw which we assume in this discussion, excessive speed tends to increase the capacity for milk, giving a comparatively rich cream, but a reduction in speed will give a larger proportionate amount of cream which will test less. While there is nothing gained by excessive speed, the greater the reduction of the number of turns below normal, the greater is the loss of butt erf at in the skim milk. Table IV. Average Per Cent, of Butterfat Lost in Skim Milk at Different Speeds. Turns of Crank Test 10 too high, .029 per cent. Normal, .029^ 10 too low, .12 20 too low, .21 3. Cleaning of Separator. It is a noteworthy fact that many users of hand separators are negligent in its care, and the idea seems to be abroad that it is un- necessary to wash them more than once a day or once in two or three days. Nothing could be farther from the truth. Even when the bowl is rinsed with warm water, there remains a coating of slime and milk on the interior parts which readily undergoes decomposition. When next used, the warm cream in passing becomes contaminated with bacteria from this source and it is injured beyond repair. Such cream may be dangerous to health and it is certainly unfit for butter- making. The repulsiveness of such a practice should be enough to condemn it it to all intelligent dairymen. However, there is also an economic loss caused by an unclean separator bowl which makes careful washing necessary each time it is used. With an unwashed separator, butterfat losses in skim milk are increased. The following averages of a series of trials on machines in otherwise good running condition show nearly three times as much loss from unwashed as from washed machines. 132 UNIVERSITY OF CALIFORNIA — EXPERIMENT STATION. Average per cent, of fat in skim milk : Washed each time used, .038 per cent. Washed once per day, .10 From this it is obvious that regular washing as described for all dairy utensils is essential to best results with the centrifugal cream separator. 4. Bate of Inflow. Each machine has a rated capacity and any tendency to force milk through in greater amounts or to reduce the inflow to any extent below normal may have serious results. It is important that each operator note the rated capacity of his machine and regulate the inflow accordingly. Forcing milk through in excess of capacity tends toward the production of a thinner cream than that of normal inflow, while a reduced inflow, other things being equal, gives a thicker cream. Decreasing inflow below a certain point does not prevent separation in the bowl, but the skim milk and cream are likely to escape together through the skim milk outlet. Table V. Effect of Excessive or Reduced Inflow. Average i Butterfat J Cream 23% Large inflow > Skim milk Normal inflow 145% f Cream 29% Small inflow | Skim milk .028% f Cream 30% )Skim milk .027% 5. Temperature of Milk. Warm milk separates more completely than cold because it is more fluid. All standard separators will do more efficient work when the temperature of the milk is between 80° and 90° than at any lower temperature, and any claim that efficient work can be obtained when lower temperatures are employed is very doubtful. Variations in test due to temperature are perhaps not so marked as those due to speed. Not more than three to four per cent, variation in the cream is due to temperature under ordinary conditions. Using cold milk gives a loss of butterfat in the skim milk. The colder the milk, the less the amount of cream and the higher the test. The effect of using different temperatures upon per cent, of butterfat lost in skim milk is shown below. Temperature of Milk Average Loss 90° F. .022 per cent 75° F. .051 60° F. .12 Bulletin 209. THE C REAM SUPPLY. 133 6. Condition of the Milk. Milk as it comes from the cow is in best condition for thorough separation. It is then in a high state of fluidity and at the right temperature. Sour or curdled milk separates with difficulty, or not at all. Milk that cannot be separated while "cow warm" should be cooled to 50° F. and then heated to 85° F. previous to skimming. Slightly sour or otherwise suspicious milk must be well stirred before entering the bowl, and slight underfeeding should be practiced. 7. Richness of Cream. The richness of cream obtained from the separator is regulated by a device called the cream screw. While many other factors may affect the test of the cream, the cream screw is depended upon for securing either a rich or thin cream. However, it is not changed frequently and is therefore not the common cause of variations in test which often lead to friction between buyers and sellers. 8. Richness of Milk Separated. "The richness of the milk separated affects the quality, but not the quantity of cream and practically the same amount is obtained whether the milk has a high or low per cent, of fat." "The amount of fat lost in the skim milk is not affected to any appreciable extent by the richness of the milk separated. ' ' 9. Flushing the Bowl. It is evident that any variation from day to day in the amount of water or skim milk used in flushing the bowl at the end of the run will have a marked effect upon the test of the cream. A variation of one pint in the amount used may change the test of cream from two per cent, to five per cent., depending upon the amount of cream secured. Effect of Feed. The richness of the milk of a cow is determined by inheritance, not by feeding. It has been proved beyond question that it is impos- sible to feed so as to permanently affect the richness of the milk. If milk is not thus affected, the cream cannot be. POSSIBLE YEARLY BUTTERFAT LOSSES. The following table compares the losses incurred on a herd of forty cows for one year, when the separator is operated improperly. An average annual yield of 9,000 pounds of milk is assumed — 85 per cent, skim milk. Value of butterfat, 33 cents. 134 UNIVERSITY OF CALIFORNIA — EXPERIMENT STATION. VI. Test Amount Value How Run Skim Milk Butterfat Lost Butterfat Lost Balanced .03% 91.8 $30.29 Unbalanced .17% 520.2 171.66 10 turns too high .029% 88.7 29.28 Normal .029% 88.7 29.28 10 turns too low .12% 367.2 121.17 20 turns too low .21% 642.6 212.05 Washed each time .038% 116.3 38.37 Washed once daily .10% 306.0 110.98 Large inflow .145% 443.7 146.42 Normal inflow .028% 85.7 28.27 Small inflow .027% 82.6 27.26 Temp, milk, 90° .022% 67.3 22.21 Temp, milk, 75° .051% 156.0 51.50 Temp, milk, 60° .12% 367.2 121.17 AMOUNT OF BUTTERFAT LOST IN SKIMMILK FROM FORTY COWS IN ONE DAY NORMAL SEPARATOR MILK TOO SEPARATOR SEPARATOR SEPARATOR • WASH FIJI • 00L1> WARN BOWL TURNED , 14BS BUT ONCE SEPARATED UNBALANCED W REVOLUTION'S * DAILY 60* P. TOO LOW VALUE IN- VALUE IN' • VALPI II VALUE II , VALUE IN ONE YEAR ONE YEAR ONE YKAR Op YR4R ONE YKAR « S 24.48 ■ 145.91 $58.69 $83.14 .$102.71 The above is based on a daily yield of approximately 15 pounds of milk, with butterfat at 33% cents. The data in Table VI is for cows giving nearly twice as much milk. Bulletin 209. THE CREAM SUPPLY. 135 Under good conditions there will be an unavoidable loss of about 75 cents per cow, or approximately $30 on the herd. Any loss greatly in excess of this amount is uncalled for. MANAGEMENT OF THE CREAM. Proper facilities for handling cream to best advantage are not always at the command of the creamery patron. Where cream is intended for market purposes, it should be cooled and promptly bottled. Otherwise, the cream should be placed in clean cans and immediately cooled. Emphasis must be placed upon the word clean. Even when cans are properly washed at the creamery and not allowed to air, when opened at the farm they may give off a foul smell. It is safe to always give them another washing and time to thoroughly air before filling. Attention is called to the usefulness of the water cooler referred to in Table II, and the accompanying discussion of its use. On many farms where cream is produced, it is the only way to hold it until delivery, and a serious application of the principle there out- lined will materially improve the grade of our butter. With cream as well as milk, the fresh warm portion should never be added to that already cooled until it has been reduced to the same temperature. Then they may be mixed with safety. Otherwise, the warm cream will be the means of hastening the souring of that already DONT SKIM TOO 1 CREAM, VOLUME OF CREAM IS MISLEADING. 1 ITS T^" T THAT COUNTS* 1 IH i 1 ffe* - — "■"^ sP£ ., isxozH |4 2 /1 The jars on the right and left each contain cream representing 13 ^ oz. butterfat, as shown in the middle jar. Notice difference in volume. Skim a reasonably heavy cream. 136 UNIVERSITY OF CALIFORNIA EXPERIMENT STATION. cooled. The milk-room, where milk or cream is held and cooled, should be used for no other purpose, as decaying vegetables or other strong smelling products will surely taint the cream. PROPER CARE AND HANDLING OF CREAM IS EXACTING WORK. While it is true that careless or ignorant employees are often trusted with the milking and handling of the product, this is a dangerous practice. There is no point in the life of milk or cream where a reasonable amount of mature experience and judgment will not easily pay for themselves. Milk is so readily perishable that only trained persons should be trusted in its care. The cost of producing it makes carelessness a dangerous and expensive risk to take. Probably no form of human food is produced under conditions where skill and common sense count for more than in the production and handling of milk and cream. There are many instances where children and other incompetent persons have been employed to cleanse milk bottles and cans and fill the same for delivery. It is hard to imagine any arrange- ment calculated to produce disaster more vicious than one of this kind. This exactness applies not only to milk and cream, but to all forms of dairy products. DELIVERY OE CREAM. It is said that 99 per cent, of the cream delivered is so handled that the butter made therefrom is injured. The producer should have some interest in the delivery of his product, especially if he has given it good care and is sending it to a cooperative or other creamery where quality is recognized. It is desirable that the time from the cow to the churn be as short and conditions as favorable as possible. During a large part of the year, careful covering, and the insulation of cans as referred to in Table III, is imperative in California. It is remark- able how much may be accomplished in the way of delivering good cream if it is thoroughly pre-cooled and well insulated in transit. Why this is universally overlooked is beyond comprehension. It is not wise where the herd is small to withhold cream four or five days to get a full can. Use a smaller can and send more frequently. PRODUCERS' AND MANUFACTURERS' RESPONSIBILITY. The butter interests of the country have been struggling in recent years with a condition of declining quality. This is not as it should be. Greater care in producing, and handling the cream on the farm, and in its transportation and manufacture into butter, will positively Bulletin 209. THE CREAM SUPPLY. 137 correct it. The power to overcome these defects lies with those con- cerned with the different steps of the business. It is not that more knowledge is needed, but that a better application of facts already understood be made. The California cream producer or creamery operator who overlooks his responsibility in this regard is not serving the best interests of the industry. ACKNOWLEDGMENT. In presenting certain data in this bulletin, Bulletin 116 of the Purdue University Agricultural Experiment Station has been drawn upon. Farmers' Bulletin 201 is recommended to those who care to study further the farm separator problem. 1M ,4 ^ A satisfactory cream gathering outfit. Where the original quality of the cream will warrant it, much will be gained by insulating each can as well. STATION PUBLICATIONS AVAILABLE FOR DISTRIBUTION. REPORTS. 1896. Report of the Viticultural Work during the seasons 1887-93, with data regarding the Vintages of 1894-95. 1897. Resistant Vines, their Selection, Adaptation, and Grafting. Appendix to Viticultural Report for 1896. 1902. Report of the Agricultural Experiment Station for 1898-1901. 1903. Report of the Agricultural Experiment Station for 1901-03. 1904. Twenty-second Report of the Agricultural Experiment Station for 1903-04. BULLETINS. Reprint. Endurance of Drought in Soils of the Arid Region. No. 128. Nature, Value and Utilization of Alkali Lands, and Tolerance of Alkali. (Revised and Reprint, 1905.) 133. Tolerance of Alkali by Various Cultures. 140. Lands of the Colorado Delta in Salton Basin, and Supplement. 142. Grasshoppers in California. 147. Culture Work of the Sub-stations. 149. California Sugar Industry. 151. Arsenical Insecticides. 152. Fumigation Dosage. 153. Spraying with Distillates. 154. Sulfur Sprays for Red Spider. 159. Contribution to the Study of Fermentation. 161. Tuberculosis in Fowls. (Reprint.) 162. Commercial Fertilizers. (Dec. 1, 1904.) 165. Asparagus and Asparagus Rust in California. 167. Manufacture of Dry Wines in Hot Countries. 168. Observations on Some Vine Dis- eases in Sonoma County. 169. Tolerance of the Sugar Beet for Alkali. 170. Studies in Grasshopper Control. 171. Commercial Fertilizers. (June 30, 1905.) 172. Further Experience in Asparagus Rust Control. 174. A New Wine-cooling Machine. 176. Sugar Beets in the San Joaquin Valley. 177. A New Method of Making Dry Red Wine. 178. Mosquito Control. 179. Commercial Fertilizers. (June, 1906.) 180. Resistant Vineyards. 181. The Selection of Seed-Wheat. 182. Analysis of Paris Green and Lead Arsenic. Proposed In- secticide Law. 183. The California Tussock-moth. 184. Report of the Plant Pathologist to July 1, 1906. 185. Report of Progress in Cereal Investigations. 186. The Oidium of the Vine. 187. Commercial Fertilizers. (Janu- ary, 1907.) 188. Lining of Ditches and Reservoirs to Prevent Seepage and Losses. 189. Commercial Fertilizers. (June, 1907.) 190. The Brown Rot of the Lemon. 191. California Peach Blight. 192. Insects Injurious to the Vine in California. 193. The Best Wine Grapes for Cali- fornia; Pruning Young Vines; Pruning the Sultanina. 194. Commercial Fertilizers. (Dec, 1907.) 195. The California Grape Root- worm. 197. Grape Culture in California : Im- proved Methods of Wine- Making; Yeast from California Grapes. 198. The Grape Leaf-Hopper. 199. Bovine Tuberculosis. 200. Gum Diseases of Citrus Trees in California. 201. Commercial Fertilizers. (June, 1908.) 202. Commercial Fertilizers. (Decem- ber, 1908.) 203. Report of the Plant Pathologist to July 1, 1909. 204. The Dairy Cow's Record and the Stable. 205. Commercial Fertilizers. (Decem- ber, 1909.) 206. Commercial Fertilizers. (June, 1910.) 207. The Control of the Argentine Ant. CIRCULARS. No. 1. Texas Fever. 3. Hog Cholera. 5. Contagious Abortion in Cows. 7. Remedies for Insects. 9. Asparagus Rust. 10. Reading Course in Economic En- tomology. (Revision.) 11. Fumigation Practice. 12. Silk Culture. 15. Recent Problems in Agriculture. What a University Farm is For. 17. Why Agriculture Should be Taught in the Public Schools. 19. Disinfection of Stables. 29. Preliminary Announcement Con- cerning Instruction in Prac- tical Agriculture upon the University Farm, Davisville, Cal. 30. White Fly in California. 32. White Fly Eradication. 33. Packing Prunes in Cans. Cane Sugar vs. Beet Sugar. 35. Southern California Pathological Laboratory and Citrus Experi- ment Station. 36. 'Analyses of Fertilizers for Con- sumers. 3 7. Announcement of Farmers' Short Courses for 1908. 39. Instruction in Practical Agricul- ture at the University Farm. 46. Suggestions for Garden Work in California Schools. 47. Agriculture in the High Schools. 48. Butter Scoring Contest, 1909. 49. Insecticides. 50. Fumigation Scheduling. 51. University Farm School. 52. Information for Students Con- cerning the College of Agri- culture. 53. Announcement of Farmers' Short Courses for 1910. 54. Some Creamery Problems and Tests. 55. Farmers' Institutes and Univer- sity Extension in Agriculture. 57. Announcement of Farmers' Short Courses in Animal Industry and Veterinary Science.