So many factors affect the composition and yield of Cheddar cheese that no positive or exact statement can be made unless other facts are definitely known. The following factors affect both the composition and yield:

1. The chemical composition of the milk.

2. Amount of moisture incorporated into the cheese.

3. The amount of solids lost in cheese-making.

4. The skill of the cheese-maker.

5. The bacterial-content of the milk.

210. Composition of milk, whey and cheese.—The following Tables93 VI, VII, VIII, which are the average of forty-eight factories for the season of 1893, show the minimum, maximum and average composition:

TABLE VI

TABLE VII

TABLE VIII

Table VI shows the minimum, maximum and average composition of the milk and Table VIII the composition of the cheese made from that milk. The average composition of the cheese in Table VIII shows that it contains 37.33 per cent of water. The tendency to-day seems to be for a softer cheese so that the average would probably be higher. Table VIII also shows the wide variation in the composition of the cheese. The moisture and total solids both vary about 10 per cent. In order to judge the variation in composition, one must know the composition of the milk and the moisture-content of the cheese and then only a very inaccurate estimate of the composition of the cheese can be formed.

211. Relation of fat to casein in normal milk.—In order to understand the relation of the composition of the milk to yield of cheese, one must be familiar with the relation of the fat to the casein in normal milk. The following table94 shows the relation of fat to casein in normal milk:

TABLE IX

Table IX shows that the pounds of casein for each pound of fat are not constant but that the casein does not increase in proportion to the fat above 4.0 per cent of fat in the milk.

212. Influence of fat in milk on yield of cheese.—The following table shows the influence which fat in the milk has on the yield of cheese:94

TABLE X

Table X shows that as the fat in the milk increases, the pounds of cheese made from 100 pounds of that milk increases; but the amount of cheese made for each pound of fat in the milk does not increase. This is due to the fact pointed out in Table IX, namely, that as the fat increases in the milk the casein does not increase in the rich milk in proportion to the fat. From Tables IX and X this conclusion may be drawn: that as the percentage of fat increases in the milk the more cheese can be made from 100 pounds of that milk, but after the increase in fat gets above 4 per cent the amount of cheese that can be made for each pound of fat in the milk is decreased because the casein does not increase in proportion to the fat. No exact statement of yield can be made without first stating the moisture-content of the cheese. The losses also must be considered.

Van Slyke95 in the following Table XI shows the effect of the fat-content of normal milk on the yield of cheese. The moisture-content of all the cheeses is reduced to a uniform basis of 37 per cent. (See cut showing yield of cheese, Fig. 52.)

TABLE XI

213. Fat loss in cheese-making.—The amount of solids lost in the whey also affects the yield. The following table gives the amount of fat lost in whey with normal milk containing different percentages of fat:

TABLE XII

Table XII shows that the percentage of fat in the whey is approximately the same for milk high or low in fat. But the milk low in fat loses a higher percentage of the total milk-fat in each 100 pounds of whey.

214. Effect of bacterial-content of milk on yield of cheese.—The bacterial-content96 of the milk influences the yield by affecting both the moisture-content and the losses. If the milk is sour or has bad fermentation, the losses will be increased because the curd cannot be carefully handled, and the moisture cannot be incorporated to the extent that it can in clean milk, without injury to the quality. The proper-cooling of the milk in one instance increased the yield 0.3 pound of cheese for each 100 pounds of milk. The more moisture that can be incorporated into the cheese up to the legal limit, the greater the yield.215. Factors affecting the moisture-content of Cheddar.—The amount of moisture that can be incorporated in a curd depends on several factors.97 The following increase the moisture-content control of the cheese:

1. Cutting the curd coarse.

2. High setting temperature.

3. Low acid in the curd at time of removing whey.

4. Not stirring the curd with the hand as the last of the whey is removed.

5. Slow pressure.

6. High piling of the curd in the cheddaring process.

7. Small amount of salt.

8. Holding the curd at low temperature after the whey is removed.

9. Large amount of rennet.

10. Cutting the curd hard.

The following factors decrease the moisture-content of the cheese:

1. Fine cutting.

2. Low setting temperature.

3. High acid in the curd at time of removing the whey.

4. Stirring the curd with the hand as the last of the whey is removed.

5. Fast pressure.

6. Low piling of the curd in the cheddaring process.

7. Large amount of salt.

8. Holding the curd at high temperature after the whey is removed.

9. Small amount of rennet.

10. Cutting the curd soft.

From this discussion, it is evident that the yield of cheese from 100 pounds of milk increases with higher percentages of fat and casein in the milk, with reduced losses of solids during manufacture, with the absence of undesirable fermentations, and with the incorporation of large amounts of water.

216. Variations of the Cheddar process.—The Cheddar process, as already described, is widely employed in cheese factories. Many varieties are found, however, and varietal names are used for such products. A whole series of these forms are either locally or widely made in England and taught in the English dairy schools. Some of these varieties resemble the factory Cheddar product fairly closely; others are clearly different products. A typical series of the variations as developed in America will be considered.

In the commercial trade Cheddar cheese is usually designated by some name which indicates its size. The size of the cheese is determined by that of the hoops. The hoops vary both in diameter and height. The table on the following page shows the usual sizes of the hoops and the weight and name applied to the cheese.

217. Cheddar-type cheese from pasteurized milk.—Sammis and Bruhn98 have described a variation of the Cheddar process to overcome the difficulties of making cheese from pasteurized milk. Such milk curdles in very unsatisfactory manner unless some chemical is added to compensate for the salts lost and to offset the other changes resulting from heat. For this purpose, they found the use of hydrochloric acid satisfactory.

TABLE XIII

"The acidulation of milk with hydrochloric acid after pasteurization is accomplished without difficulty or danger of curdling by running a small stream of the acid, of normal concentration, into the cooled milk as it flows from the continuous pasteurizer into the cheese vat. One pound of normal-strength acid is sufficient to raise 100 pounds of milk from 0.16 percent to 0.25 percent acidity (calculated as per cent of lactic acid). The amount of acid needed each day to bring the milk up to 0.25 per cent acidity is read from a table or calculated from the weight of the milk and its acidity, determined by the use of Manns's acid test (titration with tenth-normal sodium hydrate and phenolphthalein). The preparation of standard-strength acid in carboy lots for this work and the acidulation of milk present no great difficulty to any one who is able to handle Manns's acid test correctly.

"After the milk is pasteurized and acidulated three-fourths per cent of first-class starter is added and the vat is heated to 85°. It is set with rennet, using 2 ounces of rennet per thousand pounds of milk, so that the milk begins to curdle in 7 minutes and is cut with three-eighth inch knives in 25 minutes. All portions of the work after adding rennet are carried out in an unvarying routine manner, according to a fixed-time schedule every day. As soon as the rennet has been added the cheese maker is able to calculate the exact time of day when each of the succeeding operations should be performed, and the work of making the cheese is thus simplified and systematized. It is possible that the routine process here described may be varied somewhat with advantage at different factories."

This cheese usually lacks characteristic Cheddar flavor or contains it in very mild form. It therefore satisfies only those who seek very mild flavored products. Efforts are now being made to find a flavor producing substance or organism which will bring the flavor of this product more nearly to that of typical Cheddar.

218. Club cheese is known by a variety of trade names. It is made from Cheddar cheese, so that it is especially liked by persons who care for strong Cheddar flavor. It has a soft texture so that it spreads easily, and is therefore much used for sandwiches. Well-ripened or old Cheddar cheese is ground in a food chopper. The older the Cheddar, the stronger will be the flavor of the club cheese. Cheese of good flavor should be used. In order to do away with all lumps in the texture, it is sometimes necessary to run the mixed cheese through the food chopper a second time. While all lumps must be worked out, care should be taken not to work the cheese so much that it will become salvy and sticky.

Usually a little pepper is added, to give the cheese a biting taste. Some manufacturers add a great variety of substances, but these are not necessary and destroy the flavor of the cheese.

Club cheese may be wrapped in tin-foil or put up in air-tight glass jars. The latter practice, while more expensive, has the advantage of making the cheese keep longer; but for local trade tin-foil is just as satisfactory as glass. In filling the glass, care must be taken not to leave any air spaces between the cheese and the glass, as this is likely to permit the cheese to mold. A glass jar can be filled and air spaces prevented by first smearing a very thin layer of cheese over the glass.

219. The stirred-curd or granular process.—The original practice as brought from England and followed in the farm dairies before the development of the factory system is now known variously as the "stirred-curd" or "granular curd" process. With the introduction of the cheese factory, as known to-day, this system was replaced by the Cheddar cheese. The old farm process is still used on some farms and in a few factories. As the name indicates, the curd for such cheeses is kept stirred so that it remains in granular condition instead of being allowed to mat as in the Cheddar process.

The early steps of the two processes are identical. They diverge at the point at which in the factory Cheddar process the whey is drawn and the curd is allowed to mat. In some factories the curd and part of the whey are dipped into a curd sink. This allows the whey to escape more easily and quickly. In the stirred-curd process, the pieces of curd are kept separated by stirring and not allowed to mat. The whey is drawn off and the stirring continued by hand. After stirring fifteen to twenty minutes, the curd becomes so dry as not to mat easily. As soon as the curd has reached this stage, the salt is evenly and thoroughly mixed with it. More salt is added than in the Cheddar process because the curd is more moist than Cheddar curd at the time of salting. The whey freely separating carries away much of the salt. The quantity of salt to use depends on the amount of whey draining from the curd. After salting, the curd is allowed to cool, with occasional stirring to prevent the formation of lumps. The advantage of the stirred-curd practice lies in the shorter time required for making cheese and in the greater yield due to increased water-content. It has several disadvantages, among them being: (1) lack of control of undesirable fermentation; if gas organisms are present, the cheeses more frequently huff than with the Cheddar system; (2) there is more fat lost while stirring the curd, hence quality and yield suffer; (3) the water is not so thoroughly incorporated, which more frequently results in mottled cheeses; (4) the body is commonly soft and "weak," shows mechanical holes, and cures too rapidly. These faults are closely correlated with the presence of higher percentages of water than in cheeses made by the Cheddar process. In other words, the stirred-curd process usually produces a cheese with higher water-content, hence more subject to the development of unfavorable fermentation than the Cheddar cheeses.

220. California Jack cheese99 is very similar to the stirred-curd or granular process. This cheese was originally made in Monterey County on the coast of California, about twenty-five years ago, in small quantities, but after it was found to sell well other counties started to manufacture it. As Monterey was the first county to make this product, it was named "Monterey" cheese. In order to distinguish the cheese made in other counties from this, it was suggested that it be given a name and, consequently, it was called "Jack" cheese. This has been accepted as its true name. The cheese is made mostly by Portuguese and Italian-Swiss, although some of the best of the variety is now manufactured near Modesto, California.

This cheese is adapted for manufacture on small dairy farms, where there is inexpensive and scanty equipment. The smaller sizes of cheese are made and ripened quickly. It has become widely used in California.

The cheese is made every morning, from evening's and morning's milk. The former is put into the cheese vat at night, and morning's milk is added as milking is going on. When the milk is all in the vat, it is immediately warmed to 86° to 88° F. and rennet extract is added (when milk has 0.2 to 0.21 of 1 per cent acidity) at the rate of 6 to 8 ounces to 1000 pounds of milk. No coloring matter is used. It is ready for the curd-knife in thirty to thirty-five minutes, its readiness being determined the same as in making Cheddar cheese. The curd is first cut lengthwise of the vat with the horizontal curd-knife and allowed to stand until the whey rises over and partly covers the curd, when it is cut again with the vertical curd-knife crosswise of the vat. It is then hand-stirred, gently at first, and the stirring is finished with the rake.

Either a steam-heating or self-heating vat is used (the steam-heating vat is preferred) and temperature increased about one degree in five minutes. The curd is heated to 98° F. in winter, and to 105° F. to 110° F. in summer. After temperature is up, it is stirred occasionally with a rake until the whey is drawn at 0.14 to 0.15 of 1 per cent acidity.

The curd is hand-stirred as soon as the whey is nearly drained off, and raked to each side of the vat to drain more thoroughly, when it is quickly stirred again to keep it from lumping or matting. Salt is now added at the rate of 1½ pounds to 100 pounds of curd, and stirred in thoroughly several times. During the salting process, cold water is allowed to run under the vat, the hot water having been run off previously.

Curd is put into cloths at a temperature of 80° to 85° F. No cheese hoops are used. Two sets of press cloths are necessary; one set is ready to use while the other is still on the cheese in the press. These press cloths are about one yard square. The press cloths are all laid out evenly one on top of the other, as many as there are cheeses. They are then taken together and spread out over the top of a large, open tin milk-pail, and pushed down in the center to the bottom of the pail, with the edges hanging over the top. A common one-gallon lard pail is used to measure the curd into the press cloths. A lard pail full will make a cheese weighing six and one-half pounds, which is the popular size. After a pailful has been put into the press cloth, the four corners are caught up with the left hand, while with the right hand the curd is formed round and the press cloth straightened and the other corners in turn taken up. The press cloth is now taken up tight over the curd with the left hand, while the cheese is given a rolling motion on the table with the right hand, pressing at the same time to expel some of the whey. This twists the press cloth tight over the curd, where it is tied with a stout string. After fixing them all (as many as there are cheeses) in this way, they are ready for the press.

The cheeses are pressed between two wooden planks, 12 inches wide, 1½ inches thick, by whatever length is required for the number of cheeses to be pressed. One plank is nailed on supports at a convenient height from the floor on a little slant for the whey to drain off better. The cheeses in the press cloths are placed at the proper distance apart so they do not touch. Then the other plank is put squarely over the top of the cheese and levers about four feet long at an interval of five feet are placed over this plank, from a cleat in the wall, on the other end of which is placed a heavy weight of about 100 pounds, which acts as an automatic pressure. The cheeses are left in the press until the next morning, when they are taken out and put on the shelves in the curing-room. The cheeses have no bandage or covering, and do not seem to crock, and they form a very good rind.

The cheese is a sweet variety, weighs six and one-half pounds cured and cures in about three weeks ready to ship, and sells at 16 to 25 cents a pound wholesale. Most of the work seems to lie in forming and rolling the curd in press cloths before pressing. Trouble is experienced by the makers, especially in warm climates in summer, in not having the milk at a uniform acidity when rennet is added. Great improvements could be made in this cheese by using an acidimeter, paraffining and curing the cheese in an even temperature, not much over 60° F.

Old and hard Jack cheese is also employed for grating and cooking, while the fresh is used for the table.

221. The washed-curd process has been developed in recent years largely in the state of New York. In this method, a regular Cheddar curd is made up to the time of milling. This curd is washed or soaked in cold water during or directly after milling. The theoretical object of this washing is to carry away bad flavors and to reduce over-development of acidity by washing away all traces of whey. However, cheese-makers soon found that it increased the yield and this led some to carry it to extremes.

After the curd has been milled, it is covered with cold water. The temperature of this water ranges from 50° F. to 70° F. The curd is stirred in this water for various lengths of time according to the judgment of the cheese-maker. This time varies from five minutes to one hour. Sometimes the vat is partly filled with water and the curd milled directly into the water. This process has certain advantages and disadvantages.

The advantages are: if too much acid has developed in the curd, this washing will reduce it so that the cheese will not be sour. Sometimes when bad flavors are present in the curd, washing will tend to overcome or remove them. Its disadvantages are: the larger yield due to excessive soaking tempts the makers to soak curd beyond the time needed to relieve the initially sour condition. Curd soaked in this way produces cheeses containing percentages of water so high as to lower their quality. This increases the yield sometimes as much as 3 to 5 per cent. Such a cheese is very soft in texture and does not cure like a Cheddar cheese which has not been washed. Part of the lactic acid, milk-sugar100 and the inorganic salts are removed by this washing. A washed-curd cheese will sometimes rot, due to the activity of the putrefactive bacteria, and to the lack of the restraining effect of the lactic acid-forming bacteria. Some washed-curd cheeses are so soft that they will not retain their normal shape.

A washed-curd cheese is never sour because the milk-sugar and lactic acid have been removed by washing.

222. English dairy cheese.—In some localities cheeses are still made on the farms. These are mostly produced after the stirred-curd process, hence are soft-bodied and open-textured. They usually weigh ten to twelve pounds and are three to four inches thick and twelve inches in diameter.

223. Pineapple cheese.—This variety derives its name from the fact that the cheeses are made in about the size and shape of a pineapple. The curd is made after the Cheddar process from either whole milk or partly skimmed milk. It is pressed in molds shaped like a pineapple. The cheeses are then hung in nets to give the checked appearance on the surface. They are rubbed with linseed oil to prevent the surface cracking, and finally are shellacked.

224. Leyden.—Among specialties, a cheese called Leyden originating in Holland is made in Michigan and New York. This is a part skim cheese heavily spiced with caraway seed. The ripe cheese is colored red as it goes to market.

225. Cheddar cheese with pimientos.—Recently some Cheddar cheeses have been made with pimientos added. This gives a mixture of characteristic Cheddar and pimiento flavors, which seems to be desired by some persons. An ordinary Cheddar curd is made and the pimientos added just before salting. The pimientos are ground rather coarsely and then added to the curd together with the liquid which was with the pimientos in the can. The pimiento should be thoroughly and evenly mixed with the curd to insure a uniform distribution and mottled color in the cheese. The salt is then applied. The remainder of the process is the same as for ordinary Cheddar cheese.

226. Sage cheese is a product flavored from the leaves of the ordinary garden sage. It is made by two methods: one, in which the sage leaves are used, and the other, in which a part of the curd is colored to imitate that given by the sage leaves, and sage oil or tea is used to give the flavor.

In the leaf method, a regular Cheddar cheese curd is made up to the time of salting. Just before the salt is added, sage leaves are mixed with the curd. The leaves should be dried and freed from stems and other coarse particles and the leaves themselves broken up rather finely. The leaves are then added at the rate of 3 ounces for every 1000 pounds of milk. Care must be exercised to see that the leaves are evenly mixed through the curd or an evenly mottled cheese will not result. The salt is then added. This sequence seems to increase the absorption of the flavor by the curd.

If these cheeses are consumed as soon as well cured, no fault can be found. On the other hand, if they are held for any length of time, yellow areas form about each piece of sage leaf; the leaves decay rapidly and spoil the cheese. This method gives a very true flavored sage cheese, the only objection being that it cannot be held in storage for any length of time without a marked deterioration.In the other method of making sage cheese, either a vat with a movable partition or a large and a small vat must be used. In many cases the receiving can is used as the small vat. After the milk is properly ripened and ready to set, one-sixth to one-seventh of the milk is put into the small vat. To this small vat, green coloring matter is added. Juice from the leaves of corn, clover, or spinach was formerly used as coloring. Consequently the manufacture of sage cheese by this method was limited to the seasons of the year when these leaves could be obtained. Now, however, the dairy supply houses have a harmless green color paste which is much cheaper and can be secured at any season of the year. The amount of color paste to use will vary from 30 to 35 c.c. for every 1000 pounds of total milk. This should be added to the small vat of milk. It gives a green milk and later a green curd.

Both vats are worked along together, until the time for removing the whey. Then the partition in the vat is removed or the small vat is mixed with the large one. The green curd should then be evenly mixed with the white one or an even green mottled cheese will not result. The curds should not be mixed until they are well firmed or the white curd will take on a greenish cast and spoil the appearance of the cheese.

After the whey is removed, the curd is allowed to mat as in ordinary Cheddar but care must be exercised to pile the curd so that it cannot spread or "draw" out. If it does draw out, the small green spots will be stretched out and large blotches or patches of green will be the result. The cheese-maker must watch the curd closely or he may not secure the much desired small green mottles. When the curd is well matted, it is milled as in Cheddar. Just before the salt is added, the sage extract is applied to the curd.

The sage extract can be obtained from dairy supply houses, or a sage tea can be made by steeping the sage leaves. In many cases the commercial extract gives the cheese a strong disagreeable flavor, but not a true sage flavor. The sage tea gives a flavor more like that of the leaves themselves. Too much of the extract or the leaves will give a very rank flavor. The sage extract can best be put on the curd by means of a sprayer or atomizer with which it can be evenly sprayed over the entire surface. The extract should be applied two or three times and the curd well stirred after each application. The amount of the extract to use depends altogether on its strength; an ounce of the extract or three ounces of sage tea to 1000 pounds of milk is about the correct amount. After the extract has been added, the salt is used at the same rate as with a normal Cheddar curd and the sage curd is carried along the same as a Cheddar.

This extract method gives a sage cheese mottled with small green spots which somewhat resemble the green of sage leaves. A cheese made in this way can be held for a long time, as nothing has been added which can decay. The only objection to this method is that the sage extract may not give a true sage flavor. Therefore, the maker must try to obtain the best extract possible or make his own from the sage leaves.

227. Skimmed-milk Cheddar cheese.101—The process of making skimmed-milk cheese after the Cheddar process is varied with the amount of fat left in the milk. Before attempting to make skimmed-milk Cheddar, one should become familiar with the process for whole-milk Cheddar. Skimmed-milk cheeses are usually highly colored.

When part skimmed-milk cheese is manufactured, there is often difficulty in getting the milk in the vat to test the desired percentage of fat. Some cheese-makers skim all the milk and then put in the desired amount of cream. This practice seems wasteful, not only because of the cost of separation, but because the fat will not mix easily with the milk but will tend to float on the surface. If the fat floats, there will be a large loss. After a very few trials an operator can tell about how much of the whole milk must be skimmed in order to have the mixed skimmed-milk and whole milk test the desired percentage of fat. The necessary percentage of fat in the mixed milk to produce cheese of a certain grade can be determined by testing the cheese by the Babcock test. (See Chapter XIX.)

228. Full skimmed-milk Cheddar cheese.—In the summer there is not much demand for full skimmed-milk cheese, but it is made in large quantity in winter. The method of manufacture is as follows:

Skimmed-milk as it comes from the separator is at a temperature of about 88° to 90° F.; it is ripened and set at this temperature. It is ripened rather highly on the acid test, from 0.18 to 0.20 of 1 per cent, and to correspond on the rennet test which will not be many spaces. In about twenty-five to thirty minutes it is coagulated ready for cutting. The curd of skimmed-milk cheese is cut a little softer than is that of whole-milk cheese. Milk is usually set at 88° to 90° F. The curd is not ordinarily cooked above this temperature. If the milk was 84° to 86° F. when set, then the curd should be raised to 88° to 90° F. The curd firms in the whey very rapidly. When firm enough, it should have a slight development of acid. On the acid test it should show 0.17 to 0.19 per cent, and on the hot iron ?8 to ¼ of an inch. The milk should be ripe enough or starter enough should have been used, so that the acid will continue to develop in the "pack" very rapidly. During the cheddaring process the curd is piled more rapidly and in higher piles than is customary with whole-milk cheese. This is necessary to incorporate or assimilate a large percentage of water or whey in the cheese. Therefore the process of skimmed-milk Cheddar cheese is much shorter. More acid is developed with the skimmed-milk than with the whole-milk cheese because it seems necessary to develop proper texture. If the acid is not developed sufficiently, the cheese will be very rubbery and cure very slowly, in which case bad fermentation and flavor may and often do develop. The curd is turned, piled or cheddared in the vat until it begins to become meaty and fibrous. If there is danger of too much acid, the curd may be rinsed off with water. It is then milled and salted at the rate of 1 or 1¼ pounds of salt to the curd from each 1000 pounds of milk. The remainder of the process is the same as that for making whole-milk cheese.

229. Half skimmed-milk Cheddar cheese.—No definite directions can be given for the manufacture of part skimmed-milk cheese, because the process varies with the amount of fat left in the milk. As the fat is decreased, the process becomes more like that for making full skimmed-milk cheese; as the fat is increased, the process becomes more like that for whole-milk cheese. However, the process of making half skimmed-milk cheese is about midway between the two. The milk is ripened more than it would be for whole-milk cheese, usually until it tests from 0.15 to 0.17 of 1 per cent acid. The curd is coagulated and cut the same as for the other skimmed-milk cheeses. It is cooked to a temperature just sufficient to firm the curd, usually from 94° to 96° F. The lower the temperature at which the curd can be cooked and yet become firm, the better is the texture of the cheese. When the curd has firmed enough, or when sufficient acid development, from 0.15 to 0.17 of 1 per cent, has taken place, the whey is removed. The curd is then turned, piled or cheddared. A skimmed-milk curd may be piled much more rapidly than a whole-milk curd without danger of injuring it. When the curd becomes meaty or fibrous, it is milled. It should be salted at the rate of 1¼ to 2 pounds of salt to the curd from each 1000 pounds of milk. The remainder of the process is the same as that for making whole-milk cheese.

The cheese-maker should observe the following points when making skimmed-milk cheese: (1) Have clean-flavored sweet milk; (2) use clean-flavored commercial starter; (3) ripen the milk sufficiently, but not too much; (4) firm the curd at as low a temperature as possible; (5) have the curd properly firmed when the whey is drawn; (6) cheddar the curd faster than the curd from whole milk; (7) make the cheeses all the same size; (8) keep the cheese neat and clean in the curing-room.

230. Yield and qualities of skimmed-milk Cheddar cheese.—The results of skimming different percentages of whole milk containing varying percentages of fat are given in the following table. As the percentage of fat in the milk decreases, the yield of cheese also decreases, according to the table. As the percentage of fat decreases in the milk, the percentage of moisture in the cheese increases, showing that moisture is substituted for fat. The yield of cheese from 100 pounds of milk is also given in this table. This yield varies with the amount of moisture incorporated into the cheese, the amount of solids not fat in the milk, and the solids lost in the whey.

TABLE XIV

In some creameries and cheese factories, the milk is skimmed and the cream made into butter and the skimmed-milk into cheese by the Cheddar process. In making cheese without the milk-fat, it is difficult to standardize a method that will produce the flavor and body of the whole-milk Cheddar cheese. A skimmed-milk cheese lacks the softness and mellowness of texture of the whole-milk product. It is very likely to be tough, dry or leathery. It is attempted to remedy this defect by incorporating more moisture into the skimmed-milk cheese. The added moisture tends to replace the fat in giving a soft mellow body. It requires skill on the part of the cheese-maker to incorporate moisture to take the place of the fat in giving the cheese mellowness and smoothness of body.

The grades of skimmed-milk cheese vary between rather wide limits—from those made entirely of skimmed-milk to those made of milk from which only a small amount of fat has been removed and which are almost like whole-milk cheese. Because of the gradations of skimmed-milk cheese, it is difficult to make anything but general statements and to base comparisons with whole-milk cheese.