FERMENTED MILK 509 



the following morning the milk should be curdled with a thick, 

 somewhat stringy curd with a sharp, acid taste. 



(5) Heat 1 pint to 1 quart of milk as in (1), cool and add 1 

 teaspoonful of the curdled milk obtained in (4). 



Hold this milk as before, and when it has curdled break up 

 the curd by shaking vigorously in a fruit-jar. 



This process may be repeated so long as the curdled milk 

 has a smooth, acid curd free from undesirable flavors and par- 

 ticularly the yeasty flavor and odor characteristic of bread 

 dough. The so-called Bacillus bulgaricus, under favorable 

 circumstances, will suppress other bacteria by its vigorous acid 

 formation, but yeasts are favored by the acid condition of the 

 milk and sooner or later make their appearance. Every pre- 

 caution should be taken to protect the milk from exposure to 

 the air and to sterilize all utensils with boiling water. When 

 evidences of yeast contamination appear, it is best to start with 

 a fresh culture. 



Yogurt may be made more palatable by adding to two parts 

 of the yogurt one part of cold water, or, better still, cold- 

 charged water, which can be bought in siphons at drug stores. 

 Sugar and lemon juice or other fruit flavor, or chocolate sirup, 

 may also be used for this purpose. The sugar should be added 

 in the form of a sirup, as granulated sugar dissolves very 

 slowly in the cold yogurt. 



In making yogurt on a large scale the process is not essen- 

 tially different except that it is advisable to carry a small cul- 

 ture, about 1 quart, to inoculate the milk to be made into 

 buttermilk. Every precaution should be taken to maintain the 

 purity of the culture. It is advisable to carry duplicate cultures 

 independently so that a good one will always be available. 



Expensive outfits for making fermented milks are on the 

 market, but while they may be convenient they are by no means 

 essential. For the smaller dairy the following procedure will 

 probably be found satisfactory : 



