PURE AND IMPURE FOODS. 



63 



brought out, as distinguished from the 

 flavor of raw milk, and it is one 

 really agreeable to, and preferred by, 

 some people. Milk that, is near the 

 souring point is made worse by being 

 heated. While the temperature is rising the 

 germs present are stimulated to increased 

 activity, and sufficient acid is developed to 

 curdle the milk. Even when heated so 

 rapidly that the germs have no time to grow, 

 there may be acid enough present to curdle 

 the milk at a warm temperature. Sour milk 

 is preferably partaken of raw than when 

 cooked. Even when there is not enough 

 acid present to curdle the milk on cooking 

 there are enough deleterious products to 

 deteriorate the flavor. Hence it is natural 

 that there is a prejudice against cooked 

 milk. 



It is of the highest importance that milk 

 that is to be heated should be as fresh as 

 possible, for cooking does not destroy the 

 deleterious products of fermentation, though 

 it kills the germs that made these products. 

 Hence the customer should insist on ob- 

 taining as pure a milk as possible. Steriliz- 

 ing milk at home, as well as pasteurizing 

 methods in the dairy itself, do not invite 

 carelessness in regard to the cleanliness of 

 dairy methods. The application of heat is 

 intended to supplement these methods, to 

 increase the purity of the milk, just as ice 

 is applied for a similar object. Each agent 

 is used in its own proper place so as to De 

 most effective. 



Heating milk for the purpose of destroy- 

 ing the germs present is effected by 

 2 methods, known as sterilization and 

 pasteurization. Pasteurized milk has the 

 same relation to sterilized milk that rare 

 beef has to well done beef. Such milk has 

 not been heated sufficiently to give it the 

 cooked taste, and its preparation is founded 

 on the fact that disease germs can be de- 

 stroyed at a temperature below that which 

 causes this cooked condition. As most of 

 the other germs in the milk are destroyed 

 at the same time, such milk is greatly im- 

 proved as regards its keeping qualities. 



Sterilized milk, properly speaking, is that 

 which has had all its germ content de- 

 stroyed. Hence if such milk be guarded 

 from further contamination, it will re- 

 main unaltered, even at ordinary temper- 

 atures, for an indefinite period. To de- 

 stroy all the germs in milk, including the 

 spores, it becomes necessary to subject it 

 to the action of live steam under pressure 

 at a temperature considerably above the 

 boiling point, 240 degrees. Such a pro- 

 ceeding is neither practicable nor neces- 

 sary in the household, as pasteurizing 

 serves all ordinary purposes. Milk, may, 

 however, be completely sterilized by re- 

 peated pasteurization. The heating is re- 



peated daily for nearly a week, because all 

 the spores present do not germinate after 

 the close of the first or even after the 

 second heating, though few remain. While 

 milk sterilized by this method, has no 

 cooked flavor, yet it is a method commer- 

 cially impracticable. 



What is generally called sterilized milk 

 is not entirely free from germs, but hav- 

 ing been subjected to a more thorough 

 heating than with pasteurization, and being: 

 guarded against further contamination, it 

 will keep longer than does pasteurized 

 milk. This is its main advantage, for it 

 has to a greater or less degree the cooked 

 flavor. 



SHIP BREAD AND HARDTACK. 



Ship bread, it is said, is made simply of 

 flour and water. A barrel of flour is wet 

 with 3*4 pails of water, making a stiff 

 dough, which is generally cut into squares 

 with a soda biscuit cutter and baked in a 

 solid oven, which should be quite hot. 

 Sometimes the dough is cut round and 

 thick. When baked the ship bread is 

 emptied into bins in the upper part of the 

 bake shop, where it is allowed to dry for 

 days, becoming practically kiln dried. It 

 is commonly packed into flour barrels and 

 sold by the pound. Often, however, a 

 skipper has the bread packed in whiskey 

 casks, especially if it is for a long voyage, 

 as the smell of the whiskey will protect the 

 bread from weevils. Vessels from the 

 Mediterranean buy American ship bread, 

 packing it into air-tight metallic casks. 

 When wanted one cask is opened at a 

 time, and thus the bread is kept for months 

 in a fairly good condition. It is often taken 

 to the coast of Africa and used in trading 

 with the natives. That used on board ship 

 is generally made from clear flour, and is 

 sweet and wholesome, but that made for 

 export, according to a trade journal, is 

 often made from a low grade of flour and 

 is dark in color. Ship bread is not used on 

 board of vessels so much as formerly, since 

 a great many vessels carry flour and bake 

 bread as wanted. 



Hard tack, used in the army, is similar 

 to ship bread, and is made, as a rule, from 

 sound, straight grade flour. During the 

 Spanish-American war it was delivered to 

 the Government in sealed tins containing 

 100 pounds each. 



There is another class of water biscuit 

 made wholly from flour and water which 

 is largely used under the name of "water 

 crackers." They are usually rather thin 

 and are well baked, and, being brittle rather 

 than soft, they require thorough mastica- 

 tion before being swallowed. Water 

 crackers are cut into a variety of shapes 

 and given different names. 



