Cheese making

Front matter

S F

.Bass

Chap._„__ .. Copyriglit No.

Preface

The American dairy school is of recent origin, the first one having been started in Wisconsin in 1891.

With the dairy school came the need of pedagogic statements of the subjects taught therein.

It fell to the lot of the author of this book to make such a statement of cheese making. His first attempt was printed in 1893 under the title of "Cheddar Cheese Making." This first attempt met with an encouraging reception and was translated into the French language by Emile Castel for the use of the Canadians in the Province of Quebec. A second and revised edition under the same name was printed in 1895, and is now nearly exhausted. In the meantime our experiment stations have turned their attention to the subject and much valuable information has been produced. The author has been confronted with the necessity of bringing out a new revision of the book by a certain date, and that under pressure of other work. He has attempted to bring Cheddar cheese making up to date, and to present for the first time a treatment of the other kinds of cheese included in the title of the volume.

Because of their relation to the subject, milk testing, and dairy bacteriology have been touched upon briefly. An exhaustive treatment has not been necessary as there are text books treating on these subjects.

This is primarily a text book and not a reference volume. To make the latter out of it would make it unwieldly for the former purpose. An analytical index, a complete table of contents, and references to original matter will, however, assist the busy man, student or instructor to look up references quickly or to find original data.

Columbus, Ohio, November 1, 1900.

vii

TABI^E OF CONTEXTS.

Chapter I. — The Constitution of Milk

1. Purpose of milk. 2. Composition. 3. Man's use of milk. 4. Albuminoids. 5. Casein. 6. Albumen. 7. Albumose. 8. Ash. 9. Milk sugar. 10. Fat. 11. In Emulsion. 12. Creaming of milk. 13. Effect of fat on quality of cheese. 14. Effect of fat on quantity of cheese. 15. Colostrum milk. 16. Curd. 17. Whey. 18. Composition of whey. 19. Losses of fat in whey. 20. Whey from Swiss cheese. 21. Constituents recovered in cheese.

Chapter II. — Secretion and Contamination of Milk

22. Structure of the udder. 23. Secretion of the milk. 24. Time of secretion. 25. Cause of bad flavors. 20. From food eaten. 27. Flavors; by absorption. 28. Bacterial infection. 29. Varieties of bacteria in milk. 30. How milk is infected. 31. The Wisconsin curd test. 32. Care of milk. 33. Aeration. 34. Varieties of aerators. 35. The barn air. 36. Keep cows clean. 37. Cooling the milk. 38. Covering the cans. 39. Kinds of utensils. 40. Care of utensils. 41. Factory cleanliness. 42. Rubber boots. 43. Scrubbing the floor. 44. Soaps. 45. Scrubbing brushes. 46. Towels, 47. Watch the corners. 48. Shelves for trinkets. 49. How to kill moulds. 50. Antiseptics. 51. To prevent dust. 52. Factory surroundings.

Chapter .III. — Milk Testing.

53. Rapid progress. 54. The Babcock test. 55. The bottle. 56. The pipette. 57. The acid measure. 58. The centrifuge. 59. To make the test. 60. Strength of acid. 61. Speed of the centrifuge. 62. Reading the fat. 63. Testing cheese. 64. Quevenne lactometer. 65. Board of health lactometer. 66. Detecting watered milk. 67. Composite samples. 68. Milk thief. 69. Sample jars should be marked to prevent mistakes. 70. Milk samples, how preserved.

Chapter IV. — Enzymes

71. Two kinds of ferments. 72. Galactase. 73. Rennet extract. 74. Rennets, how preserved. 75. How rennet extract is made. 76. Reliable brands to be preferred. 77. Effect of heat on rennet. 78. Rennet does

ix x Table of Contexts.

not exhaust itself. 79. Effect of acidity on the action of rennet. 80. Rennet extracts not alike. 81. Rennet action deoendent on three things. 82. J. B. Harris discovers the rennet test. 83. Rennet a powerful agent. 84. Glass graduates for measuring. 85. The Monrad rennet test. 80. Use thermometer to stir milk. 87. The Marschall rennet test. 88. How to make the test. 89. Marschall tests not alike. 90. Errors to be avoided with Marschall apparatus.

Chapter V. — The Deportment of Rennet

[H. Experiments in rennet action. 92. Effect of acid and alkali. 93. Effect of water in milk. 94. The effect of salt (NaCl). 95. The effect of temperature. 96. Effect of Anesthetics. 97. Thermal Destruction point. 98. Effect of strength of rennet solution. 99. Soluble calcium salts required for rennet action. 100. Effect of milk preservatives.

Chapter VI. — Cheddar Cheese

101. History of Cheddar cheese. 102. Rise of factory system; in New York. 103. In Ohio. 104. In Wisconsin. 105. Two processes of manufacture. 10(3. Cheddar system proper. 107. Test for overripe milk. 108. Stir milk to keep cream down. 109. Ripening the milk. 110. How to ripen milk to the right point. 111. Definition of a starter. 112. What to use for a starter. 113. Lactic ferment starter. 114. What not to use for a starter. 115. Milk must not be too ripe. 116. Adding the color. 117. Setting the milk. 118. Rennet should be diluted. 119. When the curd is ready to cut.

Chapter VII. — Cutting and Heating the Curd

120. Firming the curd. 121. How to cut a fast working curd. 122. Use horizontal curd-knife. 123. How to insert the horizontal knife. 124. How to take the knife out. 125. How to insert the perpendicular. knife. 120. Rapidity of stroke a factor. 127. Keep curd moving. 128. When to begin heating. 129. Cooking an over ripe curd. 130. Stirring the curd. 131. Curd rakes. 132. McPherson curd rake. 133. How to tell a proper cook.

Chapter VIII.— Drawing the Whey— Dipping and Milling the Curd

134. Measuring acid. 135. Threads due to acid. 130. Result of too much acid. 137. Curd racks. 138. Racks, how used. 139. Cutting the curd into blocks. 140. Turning the curd. 141. Pin-holey curds. 142. Washing curds. 143. Use of a curd sink. 144. Proper form of curd sink. 145. How to fill a curd sink. 140. Keep the curd warm. 147.

Table of Contents. xi

Piling curds. 148. When a curd is ready to mill. 149. Description of curd mills. 150. Pohl mill. 151. Whitlow mill. 152. McPherson mill. 153. Gosselin mill. 154. The Harris mill. 155. The Fuller mill. 156. The Barnard mill. 157. The Kasper mill. 158. Advantages for and objections to knife mills. 159. Stirring the curd. 160. Time to mill. 161. Effect of dry acid. 162. How to expel gas. 163. Steaming curds.

Chapter IX. — Salting and Pressing the Curd

I(i4. Condition of a curd for salting. 165. What salt is. 166. Where salt comes from. 167. Impurities in salt. 168. What salt does to cheese. 169. Effect of too much salt. 170. Curds not always salted the same amount. 171. Salt should be evenly distributed. 172. Application of salt. 173. Temperature for salting. 174. Conditions of salted curd for pressing. 175. Removing fat. 176. Curd must not be too warm. 177. Curd must not be too cold. 178. Common packages of cheese. 179. Kinds of bandage used. 180. How the bandage is put onto the cheese. 181. Cheese must be the same size. 182. Tighten the press slowly. 183. Dressing the cheese. 184. The Wilson hoop. 185. How to eet cheese dry. 186. Do not pound the hoops. 187. Greasing the cheese. 188. Cracks in cheese. 189. Cheese in cold storage. 490. Cleaning mouldy cheese. 191. Cheese cloth circles. 192. Press cloths. 193. Keep a daily record.

Chapter X. — Curing and Shipping the Cheese

194. Proper temperature. 195. Curing at different temperatures. 196. Curing shelves, how made. 197. Arrangement of cheese. 198. Moisture in curing room. 199. The Hygroscope. 200. The Psychrometer. 201. Condition of the curing room air. 202. Supplying moisture. 203. Cheese, how boxed. 204. Scale boards. 205. How cheese are weighed. 206. Marking of weights. 207. Buyer's stencil. 208. How to sell cheese.

Chapter XI. — Judging Cheese

209. Ideal cheese. 210. Flavor. 211. Texture. 212. Salt. 213. Color. 214. Gross appearance. 215. Wisconsin factory cheese makers' scale. 216. Corky cheese. 217. Hard, crumbly or mealy cheese. 218. Weak bodied, pasty cheese. 219. Cracked cheese. 220. Poison cheese.

Chapter XII. — Hints on the Construction and Operation of Cheese Factories

221. One difficulty in making good cheese. 222. Too many small factories. 223. Poor buildings. 224. Poor foundations. 225. Whey tank. 226. No hot water. 227. Ontario cheese factories. 228. Good xii Table of Contents.

foundations. 221*. Dimensions. 230. Store room. 231. Curing room. 232. Sills. 233. Curing-room floor. 234. Vat-room floor. 235. Curing-room walls. 236. Doors and windows. 237 Joists.. 238. Stone cellar. 239. Curing cellars. 240. Cellar, how ventilated. 241. Sub-earth ducts. 242. Use of a well. 243. Number and size of tiles. 244. Electric fans for driving air. 245. Boiler room. 246. Building should be raised. 247. Water supply. 248. Hot wafer. 249. Sewer. 250. Blind-well. 251. Sewer trap. 252. Sewer in clay soils. 253. Whey tank, how built. 254. Elevating whey. 255. Bath room. 256. Equipment. 257. Water boxes of vats should be lined. 258. Curd sinks. 259. Pressing flats 260. Sink, how made. 261. Milk, how lifted. 262. Milk testing. 263. Appliances needed. 264. Curing shelves. 265. Cost of factory.

Chapter XIII. — Organization of Cheese Factory Association

266. Plans of operation. 267. By-laws for a cheese factory association. 268. Test committee. 269. Quorum. 270. Rates for making. 271. Figuring dividends. 272. Factory statement.

Chapter XIV. — Swiss Cheese — Its Characteristics

273. Sweet curd cheese. 274. Switzer, where made. 275. Description of Switzer cheese. 276. Determining quality of cheese. 277. Flavor. 278. Texture. 279. Color. 280. Grades of cheese. 281. How cheese is tried.

Chapter XV. — Swiss Cheese — From Milk to Curing Cellar

282. Selection of the milk. 283. Cause of Glaesler cheese. 284. Rennet test should be used. 285. Use of a starter. 286. Test of rennet solutions not correct. 287. Swiss kettles. 288. Filling the kettle. 289. Setting the milk. 290. Cutting Swiss curd. 291. The Swiss harp. 292. The wire stirrer. 293. Another method of cutting. 294. Inserting the wooden brake. 295. Cooking the curd. 296. Testing the curd for firmness. 297. Dipping the curd. 298. Pressing drum Swiss. 299. Pressing block Swiss. 300. Marking cheese. 301. Salting the cheese in brine. 302. Salting with dry salt.

Chapter XVI. — Swiss Cheese — Work in the Cellar

303. Starting the eyes. 304. Reason for making block Swiss. 305. Handling on the shelves. 306. The second cellar. 307. Handling block Swiss in the cellar. 308. Length of curing period. 309. Boxing drum Swiss. 310. Boxing block Swiss. 311. Whey butter.

Table of Contents. xiii

Chapter XVII. — Brick Cheese

312. Characteristics of brick cheese. 313. Quality of milk required. 314. Milk when received. 315. Quantity of. rennet required. 31(3. How cooked. 317. Testing curd for firmness. 318. Dipping the curd. 319. Brick cheese molds. 320. Draining table. 321. Draining boards. 322. Filling the molds. 323. Pressing the cheese. 324. Salting the cheese. 325. Curing the cheese. 326. Appearance of gas; remedy. 327. Curing process. 328. How cheese is shipped. 329. Fancy styles.

Chapter XVIII. — Limburger Cheese

330. Origin of Limburger. 331. Characteristics of Limburger. 332. Kind of milk required. 333. Utensils used. 334. Setting the milk. 335. Cooking Limburger curd. 336. Dipping the curd. 337. Limburger pressing table. 338. Salting Limburger. 339. Curing Limburger. 340. Shipping Limburger. 341. Cause of putrefactive fermentation.

Chapter XIX. — Edam Cheese

342. Characteristics of Edam cheese. 343. Origin of Edam. 344. Farming in Holland. 345. Edam cheese in Holland. 346. Treatment of cheese for market. 347. Description of an Edam market. 348. Possibilities of manufacture in America. 349. Market for Edam in America. 350. Methods of manufacture. 351. Quality of milk required. 352. Handling the curd for Edam. 353. Edam molds. 354. Methods of pressing. 355. Hooping the curd. 356. Dressing Edam cheese. 357. Salting Edam. 358. Curing Edam. 359. Shelves for new cheese. 360. Length of curing period. 361. Preparing the cheese for market.

Chapter XX. — Cottage Cheese

362. Utilization of skim milk. 363. Methods of manufacture. 364. Curdling power of acid. 365. Effect of fat on per cent of acid in milk. 366. Abnormal fermentations. 367. Measuring the acidity. 368. Setting the milk. 369. Curdling the milk. 370. Dipping the curd. 371. Marketing the cheese.

CHAPTER I. The Constitution of Milk

1* Purpose of milk.

Cow's milk is given for the primary purpose of nourishing the young calf until it can seek other food in variety.

2. Composition.

One might therefore expect to find that it contains all the food elements necessary for the building up of the young animal's body. An analysis reveals the presence of water, for the young animal's body is in the largest proportion composed of water ; ash for the bones ; nitrogenous material in the form of casein, albumose and albumen to nourish the muscles, hair, hoofs and horns ; and carbonaceous matter in the form of sugar and fat to maintain the heat of the body.

The following table will give a fair idea of the average composition of milk as delivered to a New York cheese factory; the figures being taken from Bulletin 82, December. IS!) I, Geneva, New York Experiment Station :

Table Showing Averacje Monthly Composition ok Milk.

Month.

s .

'/3 c W V o a . o rt

CU o

Per cent Solids — not Fat.

Per cent Nitrog-en Compounds.

u r.

DhO a %

u d

u S3

V .-i a °

u s

w s>

V —

Per cent Sug-ar, Ash, Etc.

May

87 40

12 60

3.63

8.97

3.14

2.44

0.32

0.38

5.83

June

87.53

12 47

3.55

8.92

3 07

2 35

0.29

0.43

5.85

July

87.63

12.37

3.59

8.78

3.00

2 27

0.29

0.44

5.78

August

87.51

12.49

3.78

8.71

3 05

2 32

0.31

0.42

5.66

September. .

87.33

12.67

3.75

8.92

3.10

2.41

0.34

5.82

October

86.87

13.13

4.00

9.13

3.36

2.60

0.36

0.40

5.77

Cheese Making.

This table shows that the total solids in the milk varies between 1? and 13 per cent, and the fat varies between 35 and -17 per cent. These are averages for the milk in the vat at the factory. Individual cows or herds may produce milk varying considerably from these averages. In the table the sugar, ash, etc., are combined. Approximately speaking milk contains 5 per cent of nilk sugar and .7 per cent ash.

The following chart shows how the different constituents of the milk are usually grouped with an approximate relation to their use as food in the animal economy. Thousands of milk analyses are on record, but these van- some with conditions of location, etc., so that it would be difficult to give an absolutely correct average, but the figures here given are within the range of usual variation.

MM

Water! 87%/

/Solid

13% s<

/Solids

rjot pat

ir/

Ash .it

CcLseinZ.1%

Use in Animal economu (Wo-ier of

^IBones

Muscles Tendons or

Trofein

^IUcn.3l^l Ha,r r

HoojS Horns r Heat

Fat

/llJbwmose h\ .Sugari./c

3. 3Ian's use of milk.

Man has diverted milk from its normal purpose (the nourishment of the calf) and uses it for a number of food products for himself. The cow normally gives enough milk in quantity and duration to nourish the calf until it can care for itself and then dries up ; but by artificial means the cow has been accustomed to the habit of giving milk in larger quantities and for a longer period, and the cow that has not acquired this habit satis-

The Constitution of M'i'lk. 3

factorily is not a financial success. Let us examine the several components of the milk.

4. Albuminoids.

The albuminoids or protein contain the nitrogen of the milk and may be divided into three parts ; namely, the casein, albumen, and albumose.

5. Casein.

The casein is the part of the milk that is curdled by rennet or weak acids. Commonly speaking it is said to be dissolved in the water of the milk, but this is not strictly true. If milk be filtered through a porcelain filter it will leave a gelatinous mass in the filter. This is the casein ; or, if skim milk be revolved for a long time in a separator bowl, a layer of casein will be deposited on the walls of the bowl. Casein is dissolved in solutions of borax, sodium phosphate, and alkalis. It is used commercially as a sizing for paper.

6. Albumen.

By referring to the preceding tables (2) it will be seen that the casein does not constitute all of the protein of milk. When milk has coagulated by rennet the casein is precipitated. If the whey be heated to 180° F. another precipitate will be thrown down. This is the albumen. It is much like the white of an egg which is coagulated by heat. It is in solution until the heat precipitates it. It probably accounts for part of the burnt taste of boiled milk. Albumen cannot be incorporated in Cheddar cheese without giving the conditions of sour cheese.

7. Albumose.

Chemical analysis reveals the fact that milk contains an albuminous substance not coagulated by rennet or heat. To this substance the name of albumose has been applied.

8. Ash.

The ash is the bone-forming part of the milk and consists largely of phosphates of calcium and potash. There are some chlorides. Although the ash is in small proportions in the milk it is of great importance in cheese making. Part of the calcium salts are supposed to be suspended in fine particles in the milk or held in combination with the casein, but a part is certainly held in solution and on this solubility of calcium salts depends the property of coagulation by rennet. If ammonium oxalate be added to milk in sufficient quantity, the soluble calcium salts

■i Cheese Making.

will be changed to insoluble calcium oxalate, and the milk will not curdle with rennet. Similar results can be obtained by heating the milk to 180° F. When a soluble calcium salt is added, the rennet will again act — in fact will operate faster as the soluble calcium salt is increased.

9. Milk sugar.

The sugar of milk crystallizes in hard crystals, but is not as sweet as the common cane sugar. At high temperature it caramelizes, giving with the albumen, to the milk the peculiar scalded taste. It is separated from milk by evaporating whey in a vacuum pan. Commercial milk sugar is used in lactated foods, and medicines.

The fat of the milk is a mixture of several fats, mainly of stearic, palmitic and oleic acids, in combination with glycerine. With these are a number of fats that are both volatile and soluble. In this latter respect butter fat differs from the fats used in oleomargarine. Filled cheese is made by introducing oleo oils into milk in the place of the butter fat.

11. In emulsion.

The fat of milk is in emulsion — that is, it is distributed through the milk serum in the form of very small globules, which can be seen by the eve only by the aid of a powerful microscope. They vary normally in size from 1-10,000 of an inch to 1-2000 of an inch in diameter. Being so very small they must necessarily be very numerous.

Dr. Babcock estimates that in average milk there are 150,- uoii.oiio in a single drop. The average production of fat globules by the cows in the Cornell Experiment Station herd has been estimated to be 38,210,000 per second.

12. Creaming of milk.

The fat globules being lighter than the surrounding serum naturallv rise, and crowding close together form a layer known as the cream. In the manufacture of cheese it is necessary to get an eyen distribution of the fat globules at the time of coagulation by the rennet. 1!?. Effect of fat on quality of cheese.

Cheese from separator skim milk is hard and horny ; and though undoubtedly possessing food value, is too tough to be eaten.

P

< re n

-n ^ o n 3 p

2 Sg-ja

ETOTQ r 1 3

ft "1 o

re o'cri w 2 re m

re C rt p

P re n)

2 re " re'

3 es

3-fe — S

re • 5t™ re uq

ft £" H ft ^ *i 3^ re 3

Cheese made from part skim milk though rather dry, is better than this, and the cheese from full cream milk more mellow and agreeable to the taste. Cheese made from exceptionally rich milk or from milk fortified by addition of cream is still softer and more palatable. This difference in quality is recognized on the market as can be seen by the quotations, full skims ranging from 1 to 4 cents in value, and full creams 7 to 13 cents per pound. 14. Effect of fat on quantity of cheese.

About five and a half to six pounds of cheese can be obtained from one hundred pounds of separator skim milk, the amount obtainable depending on the amount of casein in the

The fat globules as seen through a microscope. The portion included in the circle is more highly magnified. The clotting is due to an albuminous substance (the fibrin according to Dr. Babcock) that collects around the globules soon after the milk is drawn from the udder.

cheese. Perhaps 5.7 lbs. would be the amount of cured cheese obtainable from such milk. Butter fat will carry about a tenth of its weight of water with it into the cheese. A rough way of estimating the probable yield of cheese from a milk of a certain test would be to multiply the per cent of fat by 1.1, and add 5.7 — the result being the pounds of cheese obtainable. For instance, from 3 per cent milk there would be obtained 3X1-1=3.3 plus 5.7 equal to 9 lbs.; and from 4 per cent milk, 4X1-1=4.4 plus 5.7 equal to 10.1 lbs.

The students of the Wisconsin Dairy School who work for dairy certificates are required to report their work each month on blanks furnished them. From 347 of these reports covering

The Constitution of M'ilk. 7

40,900,890 pounds of milk made into 3,800,000 pounds of cheese, Dr. Babcock prepared the following table :

Table Showing Per cent of Fat in Cheese from Milks of Different Composition.

Per cent Fat in

Milk.

Yield of Cheese

per 100 lb.

Milk.

Per cent Fat in Cheese.

Pounds of Cheese

for one pound

of Fat.

3.13

9.19

29.7

2.94

3.38

9.24

32.3

2.73

3.60

9.41

34.0

2.61

3.84

9.81

35.1

2.56

4.09

10.30

35.8

2.51

4.45

10.71

37.8

2.41

Average. . 3.75

34.1

2.63

It will be observed that the results with the rule given above correspond very closely to the results in actual practice. It also illustrates the difference in the quality of the cheese, for as the fat in the milk increases, it also increases in the cheese, making a mellower cheese which is more pleasing to the consumer.

The yield of cheese per pound of fat, however, decreases with the increase of fat in the milk. If this were not so the cheese could not become richer in fat with the corresponding improvement in quality.

Dr. Babcock has given a most excellent demonstration in the Eleventh Annual Report of the Wisconsin Experiment Station, that from market quotations the true value of milk for cheese is in proportion to its fat content. He says, in conclusion : "It may be stated as a general rule that it never pays to skim off part of the cream and make both butter and cheese, and further that whenever the price of butter exceeds two and one-third times the price of cheese it will pay better to make butter than cheese, no account being taken of the value of skim milk and whey. If the relative value of skim milk and whey be taken into account butter should pay better than cheese whenever its price exceeds two and one-quarter times the price of cheese. Under other conditions cheese should pay better than butter."

In Chapter XIII an illustration of the method of paying for milk by fat test is given.

Cheese Making.

15. Colostrum milk.

The first milk given by a cow just after parturition is called colostrum milk, and is much more viscous than normal milk, sometimes being as thick as syrup, and usually of a high color. The components of the milk are not in their normal proportions, the albuminoids sometimes amounting to fifteen per cent, and the specific gravity may run as high as 1.085. Under the microscope, cells which have scaled off from the inside of the udder can be seen floating in the milk, and while these dead particles are present the milk is unfit for cheese. After four or five milkings the milk will appear normal, but it should not be used for a week.

16. Curd.

The curd, or green cheese, is the coagulated casein which holds in its meshes, most of the fat, some water, and small portions of albumen, milk sugar and ash, plus salt that is added artificially when finished. The water in green cheese is about one-third of its weight. Green cheese and curd are synonymous, for the cheese is simply the curd pressed together.

Table Showing Composition ok (Jkeek Cheese.

Per cent Water.

Per cent Solids.

Per cent Solids— not Fat.

Per cent Fat.

Per cent

Casein,

Etc.

Per cent

Sugar,

Ash, Etc.

36.69

63.51

29.16

34.14

23.44

5.17

In the above table, which was compiled from the Geneva Experiment Station Bulletin 82, the sugar, ash, etc., are grouped together. Our own analyses showed the ash of cheese to vary from 2.38 to 3.85 per cent, of which ash, 2.38 to 2.68 per cent, was the natural ash of the milk, the remainder being salt that was added artificially. 17. Whey.

In the manufacture of cheese, the milk is curdled by rennet, and the curd cut into small pieces from which the liquid portion, or whey, is expelled. It consists of the major part of the water of the milk, which carries with it nearly all the soluble portions; namely, the albumen, milk sugar, ash, and also a small portion of fat, as the globules break away from the surface of the curd when it is cut.

The Constitution of Milk.

18. Composition of whey.

The average of analyses of whey for an entire season in a New York State factory was as follows: Water 93.12 per cent, total solids 6.88 per cent, fat .27 per cent, nitrogenous substances .81 per cent, ash sugar, etc., 5.80 per cent.

19. Losses of fat in whey.

At the Minnesota Experiment Station in 1892 cheese was made from normal milks of different fat content. The following table shows the losses of fat from these different milks :

Tablk Showing Losses of Fat in Milks of Different Fat Content.

Per cent fat in whey

In another series of experiments where cream was added to milk to make it test 6 per cent, the loss of fat in the whey was no greater than in the whey from normal milks like that to which the cream was added.

In all cases the richer milks made more cheese, which would of course leave less whey from each 100 pounds of milk. It is easily seen from this that the fat in rich milk can be worked into the cheese more economically than the fat from poor milk.

20. Whey from Swiss cheese.

As explained above (17) the fat that goes into the whey is the fat globules that are knocked off from the surface of the curd particles. By using the kind of a knife used in Cheddar cheese making, the fat loss can be reduced to .3 or .4 per cent instead of .7 per cent when the old Swiss harp is used.

By careful operation many makers are reducing the fat test of the whey to .2 per cent.

21. Constituents recovered in cheese.

The different parts of the milk have been discussed, together with their relation to recovery or loss in cheese making.

The following table taken from Bulletin 82 of the Geneva Station gives a very good idea of where the different parts of the milk sro to :

Cheese Making.

Table Giving General Sujdiary of Season's Results Relating to Loss of Milk-Constituents in Cheese Making.

o

■f VilH

> <o o a

_«H w

O <LI .

<u

CO "

O

O <U ifl

J3 is "i

*;.c xs t^

-gg

CO V X)

unds d in 100 Ik.

CD ~ sM a o

O ^ u oO

3 •

Vh 10

&a

SiSa

Q-i V MH a

Dhi4

Solids in Milk

12.52 3.66 3.07

6.20 0.25 0.73

6.32 3.41 2.34

49.52

6.83

23 78

50.48

Fat in Milk

93.17

Nitrogen Compounds in Milk

76.22

QUESTIONS ON CHAPTER I.

1. What are the food elements which enter into the composition of milk? 2. What is the average composition of milk? 3. What is meant by total solids? 4. Of what do the solids not fat consist? 5. How do we distinguish the difference between casein, albumen, and albumose? 6. What importance is attached to the soluble calcium salts? 7. How much milk sugar in 100 pounds of milk? 8. How does milk sugar differ from cane sugar? 9. What is the nature of butter fat? 10. In what form is the fat found in milk? 11. What is the size of the fat globules? 12. How many fat globules in a drop of average milk? 13. What can be said about the distribution of the globules at the time of adding the rennet ? 14. What is the effect of fat in the milk on the quality of the cheese? 15. What is the effect of the fat content of milk on the quantity of cheese obtained therefrom? 16. How much cheese can be made from one hundred pounds of separator skim milk? 17. How much will one pound of fat increase the weight of cheese made from the milk? 18. Give rule for calculating approximately the yield of cheese from milk of a given fat content. 10. What does Dr. Babcock say about the practice of making both cheese and butter from the same milk? 20. What is colostrum milk, and how does it differ from normal milk? 21. What is the chemical composition of green cheese? 22. What is the whey and what elements of the milk does it contain? 23. How do the losses of fat in rich and poor milk compare? 24. How may excessive losses of fat in Swiss cheese making be avoided? 25. What proportion of the various constituents of the milk go into the curd and into the whey?