Commercial Lactic Ferments 199 
ferments may gain access to the cream. As between 
the various forms of artificial starter, there is not 
much to be said. It is generally held that a starter 
made from skimmed milk is less likely to contain 
germs other than those desired than when cream, 
whole milk, or even buttermilk are used. 
With regard to the use of the various commer- 
cial bacterial ferments, there is considerable diversity 
of opinion. Their use was first recommended several 
years ago in Denmark, as a result of the researches 
of Storch, and has grown rapidly, both in Denmark 
and Germany, until at the present time a large part 
of the butter produced in the former country is made 
‘from cream first pasteurized, and then ripened with 
the aid of an artificial bacteria culture. The use 
of such ferments has now largely extended to this 
country, also chiefly through the medium of Hansen’s 
lactic ferment. 
In this country Conn has been the chief investi- 
gator of similar organisms. From 1890 to 1893* he 
isolated several organisms, the culture: of which in 
cream improved the flavor of the resulting butter 
to a greater or less. extent. In the latter year he 
discovered in a can of milk sent from Uruguay to 
the World’s Columbian Exposition at Chicago, a 
germ so much better in this respect that it alone 
has since been used, and cultures of it placed upon 
the market under the name of B.41 (Bacillus No. 41). 
A series of investigations by Farrington and Rus- 
*§torrs Agricultural Experiment Station, Reports 1890-93. 
