238 AGRICULTURAL BACTERIOLOGY. 



perience tells him how much of his culture, under proper 

 conditions, should be added to the cream to produce the proper 

 grade of ripening at the particular time when he desires to 

 churn. The advantage of this is evident to any one who has 

 managed a creamery, and in itself is regarded by many as of 

 sufficient importance to warrant the use of cultures, entirely 

 independent of any other effects. 



Second : there has resulted, as already mentioned, a decided 

 increase of uniformity in the grade of butter produced. The 

 butter-maker can depend more certainly upon producing 

 butter of a certain grade, month after month, than he can 

 without commercial cultures. It must not be understood, 

 however, that there is absolute uniformity, for variations will 

 appear. But general dairy practice in Europe has certainly 

 warranted the conclusion that the use of pasteurization and 

 pure cultures gives a greater uniformity than the making of 

 butter without their use. In addition to this increase in uni- 

 formity, it is a general belief on the part of the dairymen who 

 have used the cultures, and of those who have tested the butter 

 in countries where they are widely used, that there is an im- 

 provement in the average quality of the butter as well as in its 

 uniformity. 



Third : it has become pretty definitely agreed that the flavor 

 of butter is improved by the use of such cultures. It is some- 

 what difficult to obtain definite proof of this, owing to the un- 

 certainty of scores in butter tests. Probably the most striking 

 indication of the value of these methods is the fact that the use 

 of pasteurization and pure cultures of bacteria is being adopted 

 by the manufacturers of oleomargarine products. (See p. 248.) 

 It is evident enough that this method of the use of bacteria 

 cultures would not be adopted, at such an expense, by the 

 manufacturers of oleomargarine products if they had not satis- 

 factorily proved to themselves that an improved flavor is thus 

 obtained. In butter-making the business of individual makers 



