FLAVORS OF BUTTER 167 



subject was conducted by Rogers.' Much subsequent 

 research has been made by Rogers and his cO-workers, 

 as well as by other investigators, that confirms the first 

 results. Rogers ' reports that there is a relation between 

 the amount of working that butter receives and the fishy 

 flavor. In the latter experiments this has not been sub- 

 stantiated. His important finding was reported as fol- 

 lows : "In all cases in which the records were complete, 

 it was found that those experimental butters which be- 

 came fishy were made from high acid cream. Fishy 

 butter was made from cream acidified with lactic and 

 acetic acids. However, cream with high acidity does not 

 uniformly develop fishiness." Rogers' final conclusion 

 was : " Fishy flavor may be prevented with certainty by 

 making butter from pasteurized s\\'eet cream. Butter 

 made from pasteurized sweet cream with a starter added, 

 but without ripening, seldom if ever becomes fishy." A 

 possible reason for the latter butter not becoming fishy 

 may be that less acid remains in it. It is important to 

 know how much acid may be present in the cream from 

 which the butter is made, without causing the fishy 

 fla\'or. The following statement by Rogers, Thompson, 

 and Keithley^ sheds light on this subject as well as giv- 

 ing additional data on the relation of acidity of the cream 

 to the fishy flavor of the butter : " In a tabulation of the 

 examination of 259 samples of experimental butter from 

 cream of known acidity, of 137 samples from cream hav- 

 ing an acidity below 0.3 per cent or over, 60, or 49.2 per 

 cent, were fishy." 



' Rogers, L. A., Fishy Flavor in Butter, U. S. Dept of Agri., 

 B. A. I., Cir. 146, 1909. 



2 Rogers, L. A., Thompson, S. C, and Keithley, J. R., The 

 Manufacture of Butter for Storage, U. S. Dept. of Agri., B. A. I., 

 Bui. 148, p. 8, 1912. 



