49 



the action of lactic acid, is changed during the process of cheese making 

 intt) free paracasein (not combined with calcium). Fresh cheese, aside 

 from the fat and nu)isture, consists largely of this uncombined para- 

 casein. This compound undergoes the changes in ripening which 

 })rofoun(lly affect the whole character of the cheese. Green cheese is 

 tough, somewhat rul)bcr-like, not appreciably soluble on the tongue, 

 difficult of digestion, and lacking in flavor. In the course of ripening 

 it becomes softer, more easily digestible, and acquires characteristic 

 flavors. The exact causes of these changes are not known fully, but 

 they are due in part to rennet, in part to galactase, and in part to 

 bacterial action, either direct or through their enzyms. Flavor is not 

 formed by either rennet or galactase (reference No. 3, p. 80). These 

 changes are influenced in extent and rapidity by temperature, mois- 

 ture, amount of rennet and salt used in making cheese, and amount 

 of acid i)resent (refeience No. 16, p. 156). 



4. Iniiuence of temperature upon quality of cheese. — Cheese cures 

 more ([uickly at higher temperatures, but at the expense of flavor and 

 texture. Cheese cured at 75° F. or above loses fat by leakage. Ched- 

 dar cheese cured above 60° F. does not give the best quality. Cheese 

 cures more slowly at lower temperatures but the product is superior in 

 ([uality. Also less moisture is lost at lower temperatures. Best 

 results are secured by curing cheese below 40° F. for a period of six 

 months or more (references No. 18, p. 54, and No. 19, p. 110). 



5. Covering cheese uyith parajfin. — Loss of moisture in cheese can be 

 largely prevented by coating the cheese with a thin layer of paraffin 

 without injuring the quality (reference No. 18, p. 82, or No. 19, p. 111). 

 At higher temperatures the saving is greater and the quality is better 

 than in cheese not so treated. Another distinct advantage of using 

 parafRn is that it prevents cheese becoming moldy. Conveniences for 

 coating cheese with paraffin can be obtained from dairy-supply houses. 

 The cheese should be allowed to dry out well on the surface and then 

 dipped in melted paraffin that is at a temperature of 150° to 200° F., 

 using parafhn that has a melting point not above 120° F. From three 

 days to a week should be enough to dry out the surface of the cheese 

 before coating. 



6. Moisture in air of curing rooms. — (Reference No. 3, p. 81, or 

 No. 8, p. 100.) The relative amount of moisture in the air can be 

 determined by a hygrometer. For curing Cheddar cheese the moisture 

 should be 65 to 75 per cent of saturation. 



7. Control of inoisture arid temperature in curing rooTus. — If a cheese 

 maker cures his own cheese properly he should have a special curing 

 room, properly made and equipped. The curing room should be on 

 the coolest side of the building with the least possible outside exposure. 

 Details for construction are given in Wisconsin Experiment Station 

 Bulletin 70. The control of moisture and temperature are secm"ed 



