236 MODERN DAIRY PRACTICE. 



For pasteurized cream, 5-10 per cent. 



For non-pasteurized cream at proprietary creameries, 4 

 per cent or more. 



For non-pasteurized cream at other creameries, 5 per 

 cent or more. All vessels and utensils must be kept care- 

 fully clean. ' Normal acid starter ' is kept stoppered, and 

 the whole quantity used at once." 



This carefully-prepared method should be strictly fol- 

 lowed, even in minute details, if the full benefit is to be 

 derived from it. I must particularly warn inexperienced 

 persons against " improving the same " or " making it sim- 

 pler/' Only uncertainty is gained thereby, and the real 

 benefit is lost. 



It must finally be emphasized, in speaking of pure cult- 

 ures as fermentation starters for ripening of cream, that 

 in the majority of cases it will hardly pay the trouble of 

 applying such if the cream to he ripened be not previously 

 pasteurized. The cream may contain so large a number 

 of injurious bacteria that the favorable influence of the pure 

 culture is greatly diminished and may even be abolished. 

 Pasteurization of the cream may be compared with a fallow 

 field, in which nearly all weeds are killed, and a good acid 

 starter with ^ure and good seed. It is of but little use if 

 such seed is sown in a soil full of weed-seeds capable of 

 germination; in the same way it is of but little benefit to 

 add a pure culture to a cream containing many injurious 

 bacteria. The impurities may overpower the good seed, 

 and the result will be poor. 



