LACTIC STARTERS 43 



lactic acid-forming organisms are present, is called a 

 natural starter when used in the manufacture of dairy 

 products. To secure clean-flavored milk, the cheese- 

 maker usually selects the milk of some producer who 

 usually brings good milk and allows it to sour natu- 

 rally for use the next day. There is often a variation 

 from day to day in the milk delivered by the same 

 producer, so that the cheese-maker is not certain of a 

 uniform quality in his fundamental material. While 

 the lactic acid-forming organisms are developing, other 

 organisms may also be present in numbers sufficient to 

 produce bad flavors. If a starter has any objectionable 

 flavor, it should not be used. Natural starters very 

 commonly develop objectionable flavors which at first 

 are very difficult to recognize. When natural starters 

 with objectionable but not easily recognizable odors are 

 used, the effect may be seen on the cheese. Milk, sour 

 whey and buttermilk are materials commonly used as 

 natural starter. A common difficulty in skimmed-milk 

 cheese is caused by the use of buttermilk as a starter. 



59. Commercial starter or pure cultures. The alter- 

 native practice consists in the introduction of pure cul- 

 tures of known strains of lactic bacteria into special milk 

 to make the starter. Since these cultures must be pre- 

 pared by a bacteriologist, commercial laboratories have 

 developed a large business in their production. Many 

 such commercial brands are manufactured under trade- 

 marked names. Some of these cultures represent races 

 of lactic bacteria cultivated and cared for efficiently, hence 

 uniformly valuable over long periods of time. Others care- 

 lessly produced are worthless, or even a peril to the user. 



These organisms are usually shipped in small quantities 

 in bottles of liquid or powder, or in capsules of uniform 



