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 ⅟8 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.