72 Dairy Bacteriology. 



This slimy change is due to the growth of Streptococcus 

 Hollandicus. 1 



Alcoholic fermentations. Although glucose or cane- 

 sugar solutions are extremely prone to undergo alcoholic 

 fermentation, milk sugar does not readily decompose. The 

 more important alcoholic ferments are the yeasts, which 

 do not thrive readily in the milk, although Duclaux 2 re- 

 ports a serious case in a dairy due to this cause. 



Koumiss, a beverage originally made in the Orient from 

 mare's milk, is an example of an alcoholic fermentation 

 which is produced hy the addition of cane sugar and yeast 

 to ordinary cow's milk. It is used with success in gastric 

 troubles. In addition to the C0 2 developed which gives it 

 its effervescent qualities, alcohol, lactic acid, and casein- 

 dissolving ferments are also formed. 



Kephir is another alcoholic drink made from milk that 

 is in common use among the people of Caucasus. It is 

 made by adding to milk kephir grains, which are merely a 

 mass of fermented cells (yeasts and bacteria) that start the 

 fermentation. This milk is then mixed with fresh milk 

 and kept in leather flasks until a mixed fermentation sets 

 in. The nature of the change is not yet thoroughly under- 

 stood, 8 although it is quite probable that the alcoholic 

 change is produced by a yeast, while bacteria change the 

 casein more or less. 



Bitter milk. The presence of bitter substances in milk 

 may be ascribed to a variety of causes. A number of plants, 

 such as lupines, wormwood and chicory, possess the prop- 

 erty of affecting milk when the same are consumed by ani- 



' Milch Zeit., 1889, p. 982. 



'Duclaux, Principes de Laiterie. p. 60. 



' Freudenreich, Landw. Jahr. d. Schweiz, 1896, 10:.l. 



