22O PRACTICAL DAIRY BACTERIOLOGY 



tion, this reduction in loss more than compensating for the cost 

 of the paraffin. If the butter is packed in parchment or waxed 

 paper, soaking this also in strong brine will prevent the develop- 

 ment of the molds. The molds do not particularly injure the 

 butter, but detract much from its appearance. 



Fishy Butter. Butter that has been exported to Europe from 

 Australia has frequently been reported as having a fishy taste, 

 and a similar fishy taste has sometimes been found in American 

 butter. In all of these instances the trouble is due to the growth 

 of organisms. It is stated that Oidium lactis will sometimes 

 produce this fishy taste in butter, but a similar fishy taste has 

 been described by Rogers due to yeasts. 



BACTERIA IN OLEOMARGARINE PRODUCTS 



The oleomargarine manufacturers have found that the flavors 

 which they wish to imitate can be produced only by the proper 

 action of bacteria. Hence, for many years, they have adopted 

 methods for increasing the number of bacteria, so as to obtain 

 for their product as close an approximation to the typical butter 

 flavor as possible. The methods by which they do this are 

 closely related to those of cream ripening. 



They first place in a vat a certain quantity of milk, cream or 

 skim-milk; usually whole milk is used for the purpose, but fre- 

 quently skim-milk and sometimes, especially for special grades, 

 cream has been used. In this mass of milk is placed a consider- 

 able quantity of a starter, prepared essentially in the same way 

 as before described. The whole is raised to a temperature which 

 stimulates the growth of bacteria, and is allowed to ripen in the 

 normal fashion. In the meantime the manufacturer prepares 

 various fats, which he is to use to make up the bulk of his 

 product. These fats are not always the same, different manu- 

 facturers using different materials. In this country the founda- 

 tion of oleomargarine is chiefly cotton-seed oil, lard and stearin, 



