
BACTERIA IN THE DAIRY. mee: Sc: 
BACTERIA. IN THE DAIRY.*  —~a22 G4 
BY<Fi Ww CONN: 

V. THE RIPENING OF CREAM BY ARTIFICIAL CULTURES OF 
BACTERIA, 
Experiments upon artificial ripening of cream are not new. It 
was Professor Storch of Copenhagen (Mzlchzettung, 1890, p. 304) 
who first called attention of bacteriologists to the subject by 
using artificial cultures of bacteria for the purpose and showing 
that while some species produced an excellent aroma in the but- 
ter, others produced butter of very inferior quality. Others have 
followed this lead, especially Weigmann (Landw. Woch. Schles- 
wig-Lolstein, 1890, pp. 551 and 869) and Adametz and Wilckens 
(Landw. Jahrb., 1892, p. 131) and artificial cultures for this pur- 
pose have for some time been furnished to creameries in Europe 
and to aslight extent in this country. The exact effect upon 
butter of the numerous species of bacteria which are liable to 
occur in cream is too little known from these experiments. 
Storch and Weigmann were endeavoring to find a proper species 
for the purpose and have given us too few details concerning: 
other species. Adametz and Wilckens gave more detailed 
accounts of several species but there is still little known of the 
effect of the great bulk of milk bacteria. 
In this country very little knowledge of these general facts is 
found among dairymen. For the purpose of giving a wide in- 
formation upon the subject, the Office of Experiment Stations at 
Washington requested me to prepare an exhibit illustrating some 
of these facts forthe Columbian Exposition. In preparing for 
this exhibition a large number of experiments have been per- 
formed upon the ripening of cream by the aid of artificial cul- 
tures of different species of bacteria. These experiments are 
somewhat novel in their character and unlike any that have been 

*During the past six years investigations on the Bacteria of Milk have been conducted in 
behalf of the Station by H. W. Conn, Professor of Biology in Wesleyan University. Some of 
the results have been given in the publications of the Station, as foliows: Bacterza in Milk, 
Cream, and Butter, Bulletin 4, and. Annual Report for 1889, pp. 52-67. Ripening of Cream, 
Annual Report for 1890, pp. 136-157. A Micrococcus of Bitter Milk, Report for 1891, 
pp. 158-162. The [solation of Rennet from Bacteria Cultures, Report for 1892, pp. 106-126. 
See also The Mermentations of Milk, Experiment Station Bulletin No. 9 of the Office of the 
Experiment Station of the U. 5. Department of Agriculture. 
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