176 SCIENCE AND PRACTICE OF DAIRYING. 



been previously mentioned, butter should leave the extractor at a 

 temperature of from 20 to 21 C., and the butter-separator at a tem- 

 perature of from 16 to 17 C. In the small butter cylinder of the 

 butter-separator, the paddle apparatus of the separator, when work- 

 ing at its most favourable speed, makes 3600 revolutions per minute, 

 and in the butter-extractor the rate of revolution is still greater. 



The author has seen the butter-extractor repeatedly in operation, 

 but has not been able to examine it minutely ; on the other hand, 

 he is familiar with the working of the butter-separator. According 

 to his observation the extraction of butter by this apparatus 

 differs from the ordinary operation of churning in the following 

 points: 



(1) In the butter-separator, the separation of butter is carried 

 out by means of a mechanical arrangement, which is more violent 

 than that used in the ordinary churning. 



(2) The formation of the little lumps takes place much more 

 quickly than in the ordinary processes of butter production. 



(3) The little lumps of butter do not attain to the same size as 

 in the ordinary processes. 



(4) The cream is only subjected to the mechanical action for a 

 short time. 



The real service which the butter-separator performs consists in 

 the fact that it renders it possible to churn perfectly sweet cream, 

 and to obtain excellently satisfactory results in proportion to the 

 quantity. Although this service is an important one, it can scarcely 

 be said to mark an important advance in the practice of dairying. 

 This would only be effected if it were shown that the new apparatus 

 yielded butter, the properties of which complied with the require- 

 ments of technique, of commerce, and of flavour. The experiments 

 carried out by the author have shown that the little lumps of butter 

 yielded by the butter-separator retain far more butter-milk than 

 those little lumps obtained in churning in the usual way, and there- 

 fore that the butter of the butter-separator is, on an average, some- 

 what more watery than ordinary good butter. Even although the 

 butter-milk could be more perfectly separated from this kind of 

 butter, a point which does not seem to be unattainable, the butter- 

 separator would still probably only have a limited use, since there 

 is a very slight demand for perfectly sweet butter prepared from 

 perfectly sweet cream, owing to the fact that the public taste in 

 Germany does not lie in that direction. 



