488 BUTTER DEFECTS 



micro-organisms capable of producing this flavor. O'Callaghan 1 

 attributes fishiness in butter to the mold Oidium lactis. He 

 claims that this organism when grown in conjunction with Bacil- 

 lus acidi lactici in cream produces fishiness invariably. 



Harrison 2 classes the fishy flavor of butter with bitter, putrid 

 and lardy flavors, the causes of which he attributes to the pres- 

 ence and growth of undesirable microorganisms in the cream. 

 Jensen 3 found certain species of yeast that give butter a fishy 

 flavor. Klein, 4 speaking of oily, fishy and tallowy butter, holds 

 that all these butter defects may well be considered specific 

 forms of rancid butter, resulting from the action of bacteria. 

 Hammer 5 isolated from a can of evaporated cream, which had de- 

 veloped a fishy odor, a bacillus of the Proteus group, which he 

 named Bac. ichthyosmius. With this organism he was able to 

 reproduce the fishy odor in milk, cream and evaporated milk. 

 When inoculated into butter, either direct, or into sweet or sour 

 cream, the butter failed to show fishy odor or flavor. 



The later studies and observations relating to the causes of 

 fishy butter indicate that the direct cause of fishy flavor and odor 

 in commercial butter is attributable to chemical action rather 

 than to bacterial development. Fleischmann 6 states that fishy 

 and oily flavor is a butter defect which appears only in butter 

 made from sour cream, that it shows itself as an augmen- 

 tation of an aroma characteristic of this class of butter, carried 

 to the point where it becomes offensive to taste, and that it 

 is caused by certain species of bacteria which develop in the 

 cream during souring and associatively with the lactic acid 

 ferments. 



Rogers 7 found that in all cases where butter became fishy, 

 the butter was made from high acid cream, both in the case of 

 acid produced in the cream by bacteria, and of acid in the form 



1 O'Callaghan "Cause and Remedy of Fishy Flavored Butter." The Agr. 

 Gazette of N. S. Wales, Vol. 12, p. 341, 1901. 



O'Callaghan "Butter Classification.' The Agr. Gazette of N. S. Wales, 

 Vol. 18, p. 223, 1907. 



O'Callaghan' "That Fishy Flavor." Chicago Dairy Produce, April 25, 

 1916, p. 8. 



2 Harrison "Defects in Butter." Twenty-seventh Annual Report On- 

 tario Agr. Exp. Sta., p. 79, 1901. 



3 Jensen Die Bakteriologie der Milchwirtschaft, 1913, p. 24. 

 * Klein Milchwirtschaft, 1914, p. 238. 



5 Hammer Fishiness in Evaporated Milk. Iowa Research Bui., 1917. 



6 Fleischmann Lehrbuch der Milchwirtschaft, 1915, p. 322. 



7 Rogers Fishy Flavor in Butter. U. S. Dept. Agr., B. A. I. Circular 

 146, 1909. 



