l68 BACTERIA, YEASTS, AND MOLDS 



food, particularly fruits, are ruined by freezing under or- 

 dinary conditions. In these cases the temperature may 

 approach freezing but must never quite reach it. Such 

 food will be preserved for a whUe, perhaps for months if 

 the temperature is low, but not indefinitely. It has re- 

 cently been found that even fruit — or at least many 

 kinds of fruit — can be kept frozen indefinitely if kept in 

 a sirup containing the right amount of sugar. Another 

 method of freezing, applicable to fruit as well as various 

 other kinds of food, is a recently developed process known 

 as quick freezing. In this process the food is frozen almost 

 instantaneously by passing between two sheets of very cold 

 metal. Such frozen fruits taste almost like fresh fruit, but 

 must be consumed immediately after thawing, as they spoil 

 rapidly. 



The cold-storage plant cannot be utilized by the house- 

 wife, although temperatures nearly as low can be obtained 

 in modern mechanical refrigerators. She should always 

 remember, however, that during the winter and spring a 

 considerable part of the perishable food products purchased 

 in markets has come from cold-storage plants, where they 

 have been retained for a long period at a temperature in 

 the vicinity of freezing, or even below it. If she buys fish, 

 fowl, or fruit during the winter, in a city market, she may 

 regard it as probable that they have come from cold stor- 

 age. This is a matter of considerable importance, because 

 of the practical question of the keeping properties of such 

 material. 



It is a general belief that meats and other materials 

 that have been frozen decay very rapidly after they are 

 thawed out, and hence that food taken from cold storage 



