152 AGRICULTURE. 



lumps, and soon the buttermilk can be drawn off. The buttev 

 is washed in the churn with cold water, and then turned out 

 and worked and salted. The buttermilk contains some lactic 

 acid and casein, both of which, if left in the butter, would be 

 further acted upon by ferments, and disagreeable compounds 

 would be formed ; therefore, the buttermilk is carefully drawn 

 off, the washing is thoroughly done, and the working of the 

 butter drives off the last traces or almost the last traces. The 

 working of the butter, then, is to take out the rest of the 

 buttermilk, but it must be done carefully, so as not to break 

 the tiny grains of the butter and rub them into an oily mass. 

 Then the salting what is it for ? Salt, we know, preserves 

 food. It attracts moisture, the moisture of the buttermilk, and 

 it prevents the ferments from going on with their work. By 

 all this process we have got rid of nearly all the casein, sugar, 

 and ash ; we have still some of the water ; and we should have 

 all, or nearly all, the butter-fat that was in the milk. Any 

 sugar, or acid, or casein that is left, will in time be likely to 

 set the ferments at work and make the butter rancid or stale. 



BUTTERMILK. Since cream varies so much, according to 

 the system of getting the cream, the buttermilk will vary a 

 great deal in composition and value. It should contain very 

 little fat if the churning has been properly done, less than one 

 per cent. It will contain a little ash, quite an amount of 

 lactic acid, and some casein. The casein will vary with the 

 system of creaming. As a food, it should be used as soon 

 after churning as possible, before further fermenting is set up. 



CHEESE. In making butter, we try to take all the butter-fat, 

 and only the butter-fat, out of the milk ; in making cheese, we 

 try to take all the casein and the fat out of the milk. If we 

 were simply to take the casein out of skim-milk, we would get 

 what is called a skim-milk cheese, or a skim-cheese. Usually, 

 however, whole milk is used, and a great many different kinds 

 of cheese may be made. The milk of goats and of ewes is 



