Making the Cheese with Rennet or Pepsin
Several advantages are found in making cottage cheese with rennet or pepsin, as follows:
1. A finer-textured and more uniform cheese results.
2. Making requires less time and attention.
3. Losses of curd in the whey are reduced.
Rennet is a substance which causes milk to coagulate and may be obtained either as commercial liquid rennet or as junket tablets. The former may be purchased from a dairy-supply house, while the latter may be obtained from grocery and drug stores.
If commercial rennet is used for making cottage cheese, about 3 drops should be added to each 10 pints or pounds of milk, or 10 drops to 30 pounds of milk. The rennet, after being measured, is diluted about 40 times with cold water (a half cupful is satisfactory) before it is added to the milk. For measuring a medicine dropper may be used with good results.
If the liquid rennet can not be obtained, junket tablets may be used, one tablet having about the same strength as 1 cubic centimeter or 25 drops of the liquid. One tablet may be dissolved in 10 tablespoonfuls of cold water, then 1 tablespoonful of the mixture is sufficient for 10 pounds or pints of skim milk and 3 tablespoonfuls for 30 pounds of milk. Junket tablets are not always of the same strength, so it may be necessary to experiment somewhat before the right quantity to add is obtained.
Pepsin is a powder which has somewhat the same effect upon milk as rennet and may be used instead. It should be added at the rate of one-twelfth gram to 100 pounds of milk. For 30 pounds of milk this would be a quantity about half the size of a medium-sized pea. This should be dissolved in water and fractional portions used in a manner similar to that described for the junket tablet.
The milk is handled in identically the same manner as in the method already described with the exception that rennet or pepsin is added to it just after the starter is put in and the mixture stirred vigorously. When this is done the curd or coagulum may be poured directly into the draining cloth without cutting, heating, or stirring. If no starter is used it is desirable to let the milk stand at 80° F. for five or six hours before adding the rennet or pepsin.
When clear whey collects upon the surface of the curd in the can it is an indication that the curd is ready to be drained. At first it may not be possible to get the best results by this method, but after a few trials it should be possible to produce a fine, firm coagulum in from 12 to 15 hours.
The coagulum is now poured upon the draining rack covered with cotton sheeting. Because of the fineness of the curd a draining cloth with a smaller mesh is more desirable than the one previously described. After a short preliminary drainage of perhaps 20 minutes the ends of the cloth are unfastened and the diagonally opposite corners drawn together and tied. Moderate weights, about 25 pounds, are then placed upon the bag of curd to hasten the draining. (See [fig. 5].) A pail filled with stones or water will serve for this purpose. There is danger that the cheese curd may be pressed too dry when rennet is used, so it is advisable to watch the curd closely at this period. The pressing should be continued until the curd has reached about the same consistency as described under the preceding method.
Fig. 5.—Boards and weight for pressing cheese.
After draining, salt is added in the same way as for ordinary cottage cheese.