52 CHEESE MAKING. 
If the milk is too sweet, he can calculate about how much riper 
it must be to work just right, and in a few days he will have the 
matter entirely under his control. Cheese makers should never 
neglect to use the rennet test, for it enables them to judge defi- 
nitely the condition of their milk. 
‘When a maker is troubled with tainted milk it is often nec- 
essary to ripen a little lower than with good milk, for the bad 
flavor, as we have already learned, is due to some harmful var- 
iety of bacteria which crowd out the lactic ferments. 
110. Definition of a Starter. 
A starter is a small quantity of milk in which the lactic 
fermentation has been allowed to develop; there are therefore 
millions upon millions of the desired kinds of bacteria in a 
small quantity of it, and when these are put into the milk in the 
vat, they increase very rapidly and hasten the ripening of the 
milk. 
111. What to Use for a Starter. 
The milk for the starter should be saved from one patron’s 
milk from the morning or evening before, and should be the 
best flavored milk available, for the whole vat will be made 
like it. 
From what has been previously said (28) it will be ob- 
served that the milk selected as above is the kind of milk desired. 
If the Wisconsin curd test is used the milk that habitually gives 
good curds can be selected. Even in that case a bad fermenta- 
tion may get in. The surest way of obtaining a good starter is 
to use a pure culture of lactic ferment. 
112. Lactic Ferment Starter. 
Lactic ferment is a culture placed on the market by several 
manufacturers in this country. It is sold in large and small 
bottles. The small bottles cost less and are just as good as the 
large ones, for we can grow the culture ourselves if we once get 
a start. One or two quarts of milk should be selected as above 
and heated to 200° F. for fifteen minutes and then cooled to 
70° F. The contents of the tottle should be added to this pas- 
teurized milk. In twenty-four hours, if kept warm, the milk 
will be sour and just at the curdling point. 
