CIHM Microfiche Series ({Monographs) ICIMH Collection de microfiches (monographies) Canadian Institute for Historical IMicroraproductions / Institut Canadian da microraproductions historiquas Technical and Bibliographic Notes / Notes techniques et bibliographlques The Institute has attempted to obtain the best original copy available for filming. Features of this copy which may be bibliographically unique, which may alter any of the images in the reproduction, or which may significantly change the usual method of filming are checked below. D Coloured covers / Couverture de couleur □ Covers damaged / Couverture endommagte □ Covers restored and/or laminated / Couverture restaur^ et/ou pellicula I I Cover title missing / Le titre de couverture manque I I Coloured maps / Cartes g^ographiques en couleur □ Coloured ink (i.e. other than blue or black) / Encre de couleur (i.e. autre que bleue ou noi I I Coloured plates and/or illustrations / (i.e. autre que bleue ou noire) Planches et/ou illustrations en couleur Bound with other material / Reli6 avec d'autres documents Only edition available / Seule Edition disponible D I J\ Tight binding may cause shadows or distortion along •-^ interior margin / La reliure serr6e peut causer de D D I'ombre ou de la distorsion le long de la marge int^rieure. Blank leaves added during restorations may appear within the text. Whenever possible, these have been omitted from filming / iise peut que certaines pages blanches ajout^es lors d'une restauration apparaissent dans le texte, mais, lorsque cela §tait possible, ces pages n'ont pas 6t^ film^s. Additional comments / Commentaires suppl^mentaires: L'Institut a :iicrofilm6 le meilleur exemplaire qu'il lui a dtd possible de se procurer. Les details de cet < 'em- plaire qui sont peut-dtre unk)ues du point de vue bibli- ographique, qui peuvent modifier une image reproduite, ou qui peuvent exiger une modifkation dans la m6tho- de nomnale de filmage sont indk^ute ci-dessous. I I Cotoured pages/ Pages de couleur I I Pages damaged / Pages endommag6es D Pages restored and/or laminated / Pages restaur6es et/ou peiliculdes rri Pages discoloured, stained or foxed / b/J Pages dteolor^es, tachettes ou piques I I Pages detached / Pages d^tach^es \y\ Showthrough/ Transparence rrj Quality of print varies / D D D Quality indgale de I'impression Includes supplementary material / Comprend du materiel suppl^mentaire Pages wholly or partially obscured by en-ata slips, tissues, etc., have been refilmed to ensure the best possible image / Les pages totalement ou partiellement obscurcies par un feuillet d'errata, une pelure, etc., ont dtd filmdes d nouveau de fa^on k obtenir la meilleure image possible. Opposing pages with varying colouration or discolourations are filmed twice to ensure the best possible image / Les pages s'opposant ayant des colorations variables ou des decolorations sont film^s deux fois afin d'obtenir la meilleure image possible. This Hem ia filnwd at tha raducticn ratio checkad balow / Ca doeumant aat film* au taux da rMuction indiqu« ei-daaaoua. lOx 14x Itx 22x 26x 30x 7 12x 16x 20x 24x 28x 32x Th« eepv fllm«4 h«r« has bMn raproduead thank* to tha sanMoaity of: National Library of Canada L'axampiaira film* fut raproduit grAca i la giniroaiti da: Blbliothiqua nationala du Canada Tha imagaa appaaring hara ara tha baat quality poaaibia conaidaring tha condition and lagibility of tha original copy and in kaaping with tha filming contraet apacificationa. Original copiac in printad papar covara ara fllmad iMginning with tha front covor and anding on tha laat paga with a printad or illuatratad impraa- aion. or tha back eovar whan appropriata. All othar original copiaa ara filmad baginning on tha firat paga with a printad or illuatratad impraa- •ion. and anding on the laat paga with a printad or illuatratad improaaion. Tha laat racordad frama on aach microficha shall conuin tha aymbol —♦ I moaning "CON- TINUED"), or tha symbol V (moaning "END"). whiehavar appiiaa. Mapa. platas. eharu. ate. may ba filmad at diffarant roduction ratios. Thoso too larga to ba ontiraly included in ono oxposuro ara filmed baginning in tha uppar laft hand comor. laft to right and top to boRom, as many framas as raquirad. Tha following diagrams illustrata tha mathod: Laa imagas suivantas ont *tA roproduitas avac i* plua grand soin. eompta tanu da la condition at do la nattati da I'aaamplaira filmi, at an conformity avac laa conditiona du contrat da fUmaga. Laa aaamplairaa originaux dont la eouvartura an papiar aat imprimOa sont filmOs an commancant par la pramiar plat at an tarminant soit par la darniira paga qui comporta una amprainta d'Imprassion ou d'illustration. soit par la sacond plat, salon lo cas. Toua laa autras axamplairas originaux sont filmis an commancant par la pramiOra paga qui comporta una amprainta d'impraasion ou d'illustration at an tarminant par la darni*ra paga qui comporta una tatia amprainta. Un daa symboloa suivants apparaitra sur la darni*ra imaga da chaqua microficha. talon la cas: la symbols "^ signifia "A SUIVRE '. la symbolo ▼ signifio "FIN". Laa cartaa. planchas. ubiaaux, ate. pauvant itra filmte A daa taux da reduction OiffArants. Lorsqua la document ast trap grand pour Atra raproduit an un saul clichA. il ast film* A partir da I'angia supAriaur gaucha, da gaucha A droita. at da haut w\ bas. an pranant la nombra d'imagaa nAcassaira. Las diagrammas suivsnts illustrant la mAthoda. 1 2 3 4 5 6 Mictocorr rkowtion tbt cnakt (ANSI and ISO TEST CHART No. 2) ^ APPLIED IIVHGE '653 Eost Moin Strwl Rochester. Ne» York U609 US* (716) 482 - OJOO - Phone (716) 2M- 5989 -Fox ! t - m if- PEPARTBIENT OF AGRICULTUBE DAIRY AND COLD STORAGB COMMISSIONER'S BRa./JH OTTAWA, CANADA THE COOLL\G OF MILK FOR CHEESEMAKING BY J. A. RUDDICK AND GEO. H. BARR BULLKTI^ No. 22 Dairy and Cold Storage Commiasionera Series Published by direction of the Hon. SYDNEY A. FISHER, Minister of Agriculture Ottawa, Ont 12439—1 yjaiHRUA-RY, lOlO i I LETTEE OF TBAHSMITTAI. The Honou ruble The Miiii!»ter of Agripiilturp. Sir. — I have the honour t<» submit for your approval, the mantisoript for a bnllinial on 'The Cooling of Mili< for CheesenuilxinR.' wiiit-h has been prepared from the rt'.-iilt> of a series of experiments conducted nndi-r m.v direction by Mr. Geo. II. Barr. i'Ww'A of the D.i-'y Division, assisted by Mr. .1. (). Bouchard, of tlie dairy staff. I bcR to recommend that it l>c printed and distributed as Bulletin No. 22 ot tin Dairy and ^'old Storage scric^s. I have the honour to be, sir, Your obedient serv int, •f V. PFDDirK, Vairy and Void ■ tmmuisioner. OrtKWk, February 28, 1910. i. THE COv^iilNG OF MILK FOR CHEESEMAKING. BT J. A. lUSOICK AXU 0£0. H. BASB. INTRODUCTION. The recommendation* which will be found in those ftge^ nrc based on the rosulta of an extensive wries of experiments which were carried out by nienibcrs of the itaff of the Dairy Divii*ion during the semoiis of 1908 and 1900. Full detaiU of the exporiments, of which only a summary is given herein, will be found in the reports of tlie Dairy and Cold Storage Commissioner for 1909 and 1910. and these rejmrts will be «t'nt to any person who applies for them. Inasmuch as the recommendations referred to are against the practice of aerating or exposing the milk to the air in any manner, it may be a'vi.snble to offer a few words of explanation on that point. Tim aeration of milk intended for cheesemaking has been advocated for 20 years or more, and until recently it was generally believed to be beneficial. It is a rather curious fact, however, that one cannot find a single instance of a careful nml reliable exixriment the results of which are in favour of aeration. Belief in the practilu .^(makers have noticed that they frequently received better milk from patrons who never aerated it, than they did from those who followed the practice. By degrees hiKliiig instructors and others became convinced that aeration of milk was not only uniiecessary, but might be positively harmful. Prof. Dean of (Jiielph, after exi)eri- nitnts at the College, reported against aeration, and American experimentalists failed tr) tind any benefit in the practice. There was, however. ver>- little authoritative data upon the subject, and it was with a view of supplying this data that the experiment* alreadv referred to were undertaken. il- THE £XP£BIlfEllT8. In 1008 the experimcnU were carried rut with the milk of two hordi numbiri,,; 36 cow«. Th." two men in charge of the expcrinionti were alwayi prewnt at Uv evening milking ai.d they pernonally hnn.lk 1 the milk, keeping nccvirate recor.l- r,: temperatur*. &c. The milk of each cow wng divide.1 «i»nlly into two part, ami .ah part was treated differ.>ntly. The moniinR'n .nilk was strained, into acparate .nr- and not aerated or cooled in any way. , ,. » u i A complete equipment of chcesoroaking apparatus inrlnlinK two •mall ch.- v..te, wa» installo.1 in a spare room of the Rideau Queen chocs.' factory at 8t.u.h< Falls, Ont, of which the owner- of the herds were patron.. When the milk wn- delivered at the factory, carefui tesf- wer« made for fat. acidity and flavour tb. fermentation curd tc«t being used to determine the flavour. The milk, aecordini.' t. the treatmeni which it had received, was placed in two vats and each lot ma.io ^ sfparately. That part of the evening', milk from both farms that had been roule, onlv wa. put into one vat. v hile the part that hfid l.een treated differently was put mt the other one. The morning's milk from both farm. wa. divided equally between th, two vat.. The curd, were carefully watched for the development of ga* and flav nn and photograph, were taken of section, from the curd in each vat to .how the differ.n.rt in texture between the two. (Fig. 1. Plate 1I.> • , /, , Ji The cheese were cured in the ordinary way and for the uMinl period, after wluet they were shipM to cold storage, where they were examined from time to time ;.« to quality. , , . The results of the 1908 experiment*, carried on during June, July and AunvAl are summarized in the following table : — Table I.— Experiments on the Cnre of II ilk.— Defect, in Curds and Cheese. Milk aerated by clipping. Milk run over an aerator. Milk aerated and cooled. Milk cooled with water la ahotgun ran. Milk COolc'l in tub of w:ii( r No. Curd Tc^-ts— Not Clean Flavour GauBy Texture 18 8.3 -4% 77 -8% 22 .8-2% 88-2% is 44% 44% 10 10% 20% .■ill 6 -tv ; 6-(i'. No. of Cunls — Not Clean Klnvovir Gassy Texture 9 8S •9''; 77 -8' f, 12 50 0% 50 0% 10 40% 20% 5 I.'i Cheese — Not Clean Flavour 77 -sr/c 75 0% 60% 20% KMi'; In 1000 a different plan wns followf^d. Tiie milk supplietl by the 40 pat-on^ •j tlio factory was used. The patrons were divided irU(> two jrroup^, and each gt. ip "''I asked to treat the milk day by day as required for the various tests. For iii. t: as possible, and not to dip or stir it, while the other group was to aerate by pouriiij.l dipping, &c. The instructions to the two groups were 'iversed from time to time ' eliminate as far as possible any interference with the results by other factors. Tlii'^l experiments covered the period between .Tune 11 and August 12. 1000. The results in 1900 confirmed in |N-d mi tliiH utiuiil wiut the came of the (CiKMy ciiiulitinii in the i-iiril iiiarkeil 3 A in Fi|;. 1, I'liite II. Fio. 2. On the above stand "M per cent of the cuid tests were clean in flavour when the milk was cfKiled ithout aeration and only 17 l>er cent were clean when the milk waa dipped without csooling, 124S9-2b i 11 « 111 ir^ ■ 1 l'L4n II. Fi.i. 1. it A Curd iiiu(l»- fMiii milk cooltKl and |i«-(l liy half nf the |iatrunx. 4 A-Ciinl iiiiule (rciiii milk OKtIed without iiprittion hy the othtr half of thfiiiitroii> on Aiiguit 3, VM*,K m I i Fig. 2. Tank for Cooling Milk m Can? M It must not be assumed that the mere cooliiipr of the milk insured a good flavour in every case. Table I. shows that it did not always give that result. Cooling will not correct the bad effect of a lack of cleanliness in milking, or the use of rusty or dirty cans or utensils, any more than aeration will. The point to remember is this: ruaHtui mhi -n nearly every rase (jave decidedlu letter results than cooling and aeration or aeration alone. In no case did the cooled milk produce cheese that was inferior in flnrour to that which was aerated or abated and cooled. The plan of cooling only has thp additional advantage that it is the easiest and simplest method of handling the milk. Losses from Overripe or Tainted Milk. The losses which result to patrons of cheese factories from overripe and tainted milk are very serious, and deserve more attention than they have received from those intorosted. Table II.— Comparison of the yield from 4 vnts of normal milk with thr yield from 4 vats of overripe milk. The fat and casein tosts were the same in nil vats. Acidity of Milk. Normal Milk. . Overripe Milk. •21 ■24 Lbs. Milk. 15,969 15,71S Lbs. Cheese. l,437i 1,4U1 Lbs. Milk to 1 lb. Cheese. 11 11 11-21 Total loss on 16,715 lbs. of overripe milk equal to 148J lbs. of milk, or 13.36 lbs. of .11 'I I! -1 -I ki: Table III.— Comparison of the yield from 4 vats of normal milk with the yield from 4 vats of 'gassy' or tainted milk. The fat and ca?eiu tests were the same in all vats. \. :i!,l MilU (;:l--v Milk . Aciditv of Milk. •212 •217 Lbs. Milk. 15,311 14,673 Lb-.. Cheese. Lbs. Milk to 1 lb. Chec.-^e. 1 ,3661 1 ,294i 11 20 11 33 Loss on 1.000 lbs. pas^^y milk equal to 108 lbs. cheese. These losses are avoided if the milk is sufficiently cooled in hot weather to pre- vent it from becoming overripe. In this connection, it should be under.'^too.l that iiilk is overripe from a cheesemaking standpoint, before it reaches the stage of ta>ting We are justified in saying that the los^^os in tlies<> experiments were not as great a- thov often are in ordinary factory practice, for the reason of the greater .skill and exporienee of tho^^e in charge of the work, a* compared with the average eheesemaker, nn.l for the further reason that there was plenty of help to handle the milk to beat advantage. IP I 'i I I THE IILirSTBATIOHS. - Fig. 1, Plate I. shows a milk stand on one of the farms iiuluded in these ex|K ri ments. 'ihis stand would be generally considered to have a good location. It is surrounded by a compnratively large area of clean, grass covired yard and is si.niH distance from the stables or manure heaps. Notwithstanding these favourable .,.iii as milking was finished, there was no evidence of pa-. Fig. 2 shows a stand, not (|Mit,' so well located, being nearer to the stable yard, where the same results were (.Uaimd. These examples— and we have many others— indicate dearly that no matter how ' g<"„r the location of the milk stand is, there is always danger of infection of the niili<, unless exposure to the air is avoided. Fig. 1. Plate II. is a photograph of two pieces of curd, the particulars of wiii.h are given in the note accompanying the cut. It may be necesrary to explain, for tli,' benefit of those who are not familinr with the processes of cheese manufacture, lli,it the piece of curd marked ' .3A ' is what is known as a ' gassy ' curd, on account of tji,. numerous holes in it. caused by the development of gas, which is a product of lli' growth of a certain class of genii that get into the milk after it is drawn from the .■,.« The piece of curd marked ' 4.\ ' show.« none of these gas holes. The holes which apiw.ir in it ar«- merely mechanieal boles, wliieh arc always present in curd. This ilhiMr.i- tipn shows very clearly the bad effect of exposing the milk to the air. Fig. 2 Plate TI. shows a convenient arrangement for cooling milk by placing; ili' cans in a tank whi<-h is tilled with cold water. The cold water is conducted to th,. bottom of the tank and the overtl(.w is from the top. If water is pumped for sl..rk, the overflow from the tank can be carrieil to the water trough. BECOMHENDATIONS. 1. Evening's milk intended for the manufacture of cheese should be placed in the cans as soon as possible after milking. In warm weather, the milk should be cooled by surrounding the milk cans with cold water, or water and ice. A tub made from a barrel cut in two will serve the purpose, or a special tank, like the one in the illustration, may be made to hold several cans. If the supply of water is limited, ice may be used with advantage. Where there is plenty of cold well water, ice is not absolutely necessary, except when the milk is to be kept over Sunday. Do not dip or pour the milk. 2. The cover should be placed on the cans as soon as the milking is finished and left there for the night. There will be no clotted cream on the firface of the miik when the milk is cooled and the can is covered. 3. It is advi&able to deliver the evening's and the morning's milk in separate cans, but if for any reason the two milkings must be delivered in the same can, and the morning's milk is not cooled, the evening's milk should be cooled to 60 degrees or under. If the two milkings are delivered in separate cans, or if the morning's milk is cooled to 75 degrees, the evening's milk need not be cooled lower than 66 degrees under ordinary circumstances. The morning's milk need not be cooled when it is delivered in a separate can, and it should not be dipped or aerated in any case. 4. When milk is to be kept over Sunday, it should be cooledto 50 degrees or under. 5. A thermometer should be used to determine the temperature. Use only the special dairy thermometers made wholly of glass, and known as ' float ' ther- mometers. T * HOTEf CoTering the Cuii. Our advice to put the covers on the cans as soon as roilkinir is iinitthet). is contrury to what has been the usual practice araon^r cheesf, factory and creamery patrons. Tt has been popularly supposed that the milk should be left uncovered to facilitate the escape of ' animal heat,' ' animal odours,' and so on. On the other hand, in the hisrh class dairies where milk is bottled for direct consumption, the practice is to put the milk in a tightly stoppered bottle as soon as possible after milkinK- Our experiments proved that the best results were obtained by covering the milk. It protects it from insects, dust, falling leaves, or other dirt which may find entrance and thus carry to the milk many injurious germs of one kind and another. It also prevents the evaporation from the surface of the milk that causes the formation of a tough, leathery surface of cream, much of which is lost in the process of cheesemaking. Water for Cooling. The quantity of water that is required to sufficiently cool a given ()uantity of evening's milk depends on several conditions, such as the temperature of the water itself, whether the evening is a cool one or a warm one, and at what hour the milk is delivered at the factory in the morning. The latter point is important. Milk that is delivered at the factory at 6 a.m., as is the practice at many factories, does not require- a.s much cooling as it would if delivery were delayed two or three hours. Generally speaking, if deep well water is available at a temperature of .50 degree-* or under, a quantity equal to that of the milk will be si.fficient for the purpose. If the water is warmer, a larger quantity will be required. If the supply of water is limited, ice can be used in it to good advantage. One pound of ice hivs a cooling power in this connection equal to 8 to 10 pounds of the coldest well water. n ;1 Water a Better Cooling Medinm than Air. Water is a better cooling medium than air is. Thus, if the milk cans are >iur- rounded with water at temperature of 50 degrees, cooling is effected more quickly than i^ the cans are surrounded with air at the same temperature. Quick cooling is important. OENEEAL. No attempt is made in this- bulletin to deal with other pha'^es of the production of milk for the maniirfacture of butter or cheese. While we desire at this time to draw special attention to the importance of cooling milk and to the advisability of dis- continuing the practice of aeration, we do not \' ish to minimize the importance ot pond health in the cows, of suitable feeds, of sani; -y conditions in stables and yards, of dcnnliness in milking and in the care of utensil Tluve experiments relate to the manufacture of ciieese, but the principles laid down apply also to the handling of milk for buttermaking, or for direct consumption. Managers of creameries or cheese factories may obtain copies of this bulletin in French or English for each patron, by application to the Dairy and Cold Storage Commissioner, Ottawa. Seqnests for Bulletins should state the number required. iil LIST OF PUBLICATIONS OF TlIK : • I DAIRY AND COLD STORAGE COMMISSIONER'S BRANCH. Date iMued. No. Title. 1906 1 List of Some British Importers of Farm Products. 1905 t2 Care of Milk for Cheese Factories. 1905 f3 Care of Milk for Creameries. 1905 H Some Phases of Dairying in Denmark. 1905 5 Improvement of Dairy Herds. 1905 6 Chemical Investigations Belating to Dair/ing in 1904. 1905 7 List of Exporters of Some Canadian Products. 1906 8 Some of the Factors that Control the Water Content of Butter. 1900 to Instructions for Testing Individual Cows, Ac. 1906 10 Creamery Cold Storage. 1906 11 General Instructions re Fruit Marks Act as Amended, 1902, 1906 1 and 1908. 1906 12 Cow Testing Associations, with Some Notes on the Sampling aii| Testing of Milk. 1907 13 Sweet-Cream Butter. 1907 14 Apparatus for the Determination of Water and Fat in Butter. 1907 *15 Gathered Cream for Butter Making. 1907 16 Subsidies for Cold Storage Warehouses. 1907 17 Buttermaking on the Farm. 1907 tl8 Co-operation in the Marketing of Apples. 1907 19 The Packing of Apples in Barrels and Boxes. 1907 *20 The Use of Ice on the Farm. 1907 t21 Report of the Cow Testing Associations. 1906 Report of the Dairy Commissioner, January, 1905, to March, 1906. 1907 Report of the Dairy and Cold Storage Commissioner, 1907. 1908 Report of the Dairy and Cold Storage Commissioner, 1908. 1909 Report of the Dairy and Cold Storage Commissioner, 1909. 1907 Map Showing the Location of Cheese Factories and Creameries ii | Canada. Any of these publications will be sent fiee of charge on application to the Dairy and Cold Storage Commissioner, Ottawa, Ont. * A sufSicient number of bulletins No. 15 and 20 will be sent to the manager of | any cheese factory or creamery to supply one to each patron. t Out of print. itt