236 PRACTICAL DAIRY BACTERIOLOGY 



For these reasons, then, the cheese industry is learning the 

 prime importance of a strong lactic fermentation in milk to be 

 made into cheese, and in order to bring this about it is 

 rapidly adopting the method of using starters. The starters 

 used in cheeses are essentially identical with those used in but- 

 ter-making, and they are used in much the same way. Home 

 starters are frequently made and inoculated into the milk, and 

 the use of commercial starters is also rapidly growing. -It has 

 been suggested that acid bacteria be inoculated into the rennet 

 to prevent the growth there of undesirable bacteria. It is in- 

 teresting to find that types of lactic bacteria which are useful 

 in butter-making are not always satisfactory in cheese-making. 

 In some experiments, for example, it has been found that bac- 

 teria that give a fine flavor and aroma to butter, produce a bitter 

 taste and a ruined product when used in cheese-making. This 

 simply indicates that the types of lactic bacteria are different, 

 at least so far as concerns their final action on the casein. The 

 use of starters in the cheese industry seems to be firmly estab- 

 lished at the present time, and is practically sure to extend, for 

 it is one of the methods of safe-guarding cheese against un- 

 desirable fermentations; and it is almost sure to become recog- 

 nized as even more necessary than in butter-making. 



BACTERIA IN EDAM CHEESE 



It is an interesting fact to learn that, some years before the 

 relation of bacteria to cheese-making was studied, the Holland 

 cheese makers had practically learned the value of bacteria 

 cultures in making Edam cheeses. 1 For many years they have 

 used a starter known as slimy whey, which was added to the 

 milk that was to be made into cheese. This material contains a 

 large quantity of a species of a coccus, Strep. Hollandicus, that 

 makes the milk slimy, and when used in cheese-making regulates 

 the ripening so that the cheeses mature more rapidly and more 



1 Bockhaut and Ott de Vries. Rev. Gen. d'Lait, v., p. 1, 1905. 



