Bacteria .in Cheese. 



165 



curd and whey is continually increased by the development 

 of bacteria in the same. 



The body of green cheese fresh from the press is, to a 

 considerable extent, dependent upon the acid produced in 

 the curds. If the curds are put to press in a relatively 

 sweet condition the texture is open and porous. The curd 

 particles do not mat closely together and u mechanical 

 holes," rough and irregular in outline, occur. Very often, 



FIG. 30. L, a sweet curd cheese direct from the press. " Mechanical " holes due 

 to lack of acid development; P, same cheese fpur days later, mechanical holes 

 distended by development of gas. 



at relatively high temperatures, such cheese begin to 

 u huff," soon after being taken from the press, a condition 

 due to the development of gas, produced by gas-generating 

 bacteria acting on the sugar in the curd. This gas finds 

 its way readily into these ragged holes, greatly distending 

 them, as in Fig. 30. 



Physical changes in ripening cheese. When a green 

 cheese is taken from the press, the curd is tough, firm, but 

 elastic. It has no value as a food product for immediate use, 



