PURE CULTURE STARTERS 343 



In the first case it is possible that the bacteria already 

 there, may be of sufficiently vigorous stock to carry on 

 the fermentations independently of the added starter. 

 Such a state of affairs is likely to occur with compara- 

 tively old cream, and it is obvious that the addition of a 

 starter in cases like this may have little or no appreci- 

 able effect : the operation is not worth the trouble it 

 involves. The butter obtained where this practice pre- 

 vails is not likely to be uniform at all seasons and may 

 sometimes be of very bad flavour. 



In the second case there is perhaps less danger of 

 difficulty than where older cream is used, but irregular 

 ripening may arise from organisms which have come 

 from the farm and cowshed. The plan of adding the 

 starter to pasteurized cream, while involving more 

 expense, frees the starter from competition with adverse 

 organisms and allows those of the chosen, desired type a 

 free field for development. The keeping quality of the 

 butter is improved as most of the organisms capable of 

 giving rise to taints and bad flavours are destroyed by 

 pasteurization. A more uniform grade of butter is pro- 

 duced and can be maintained with comparative certainty 

 throughout the year. This method of using starters is 

 adopted in Denmark and other countries where there is 

 a progressive dairying industry, partly on account of the 

 economic value of a uniform product and partly because 

 the law requires the pasteurization of all milk which 

 passes through creameries, with a view of assisting in the 

 extermination of tuberculosis. The skim-milk and butter- 

 milk which may ultimately be returned to the farms and 

 consumed by susceptible young stock, is thus rendered 

 free from the bacilli of the disease. 



