UNITED STATES DEPARTMENT OF AGRICULTURE 
BULLETIN No. 319 
Contribution from the Bureau of Animal Industry 
A. D. MELVIN, Chief 
&JS^&mfU 
Washington, D. C. 
PROFESSIONAL PAPER. 
January 10, 1916 
FERMENTED MILKS. 
By L. A. Rogers, 
Bacteriologist in Charge of Research Laboratories, Dairy Division. 
CONTENTS. 
Introduction 
Therapeutic value of fermented milk. 
Food value of fermented milk 
Page. 
1 
The various forms of fermented milk. 
Bibliography 
Page. 
8 
25 
INTRODUCTION. 
Within recent years there has been a rapidly growing interest in 
the therapeutic value of buttermilk and other fermented milks, such 
as kefir, kumiss, and yogurt. This is seen in the increasing sale of 
buttermilk, in the large number of special preparations now offered 
for sale, and in the frequent discussion of this subject in popular 
and scientific publications. Buttermilk is not only consumed in large 
quantities as a beverage, but is recommended by physicians as a 
therapeutic agent in the treatment of intestinal disorders, and is in 
constant use in many hospitals. 
It is the aim of this paper to give the reader a brief resume of 
our present knowledge of this subject. The literature relating to fer- 
mented milks is already voluminous, and few persons, not even phy- 
sicians, are so situated that this can be brought together and assimi- 
lated. It will be necessary for the benefit of those having a profes- 
sional interest in the subject to include information of a somewhat 
technical nature. 
All the more familiar fermented milks are the result of an acid fer- 
mentation in which the sugar of the milk is split up into lactic acid. 
This may be brought about by the presence in the milk of varieties of 
the common lactic-acid group of bacteria, or, as in the case of yogurt, 
by special organisms ; or a yeast may be present, adding an alcoholic 
to the ordinary acid fermentation. 
8959°— Bull. 319—16 1 
