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UNITED STATES DEPARTMENT OF AGRICULTURE 
J BULLETIN : " Nor 240 
Contribution from the Bureau of Animal Industry 
A. D. MELVIN, Chief 
Washington, D. C. 
PROFESSIONAL PAPER 
July 13, 1915. 
PASTEURIZING MILK IN BOTTLES AND BOTTLING 
HOT MILK PASTEURIZED IN BULK. 
By S. Henry Ayers, Bacteriologist, and W. T. Johnson, Jr., Scientific Assistant, 
Dairy Division. 
CONTENTS. 
Page. 
Introduction 1 
Method of bacteriological analysis 3 
Method of pasteurizing in bottles 3 
Bacterial reductions by pasteuriza- 
tion in bottles 3 
Advantages and disadvantages of 
pasteurization in bottles 7 
Machinery for pasteurizing milk in 
bottles 7 
Method of pasteurizing in bulk and 
bottling while hot 11 
Comparison of bacterial reductions in 
milk pasteurized in bottles and 
milk pasteurized in bulk and bot- 
tled while hot 12 
Page. 
Prevention of bottle infection by 
bottling hot milk and by pasteur- 
ization in bottles 14 
Cooling milk which has been bottled 
hot 16 
The cream line and flavor Of pas- 
teurized milk cooled by various 
methods 23 
Bottles to be used in the process of 
. bottling hot pasteurized milk 24 
Process of bottling hot pasteurized 
milk under commercial conditions- 24 
Summary 25 
Citation to literature . 27 
INTRODUCTION. 
The process of heating milk in bottles is by no means a new one, for 
it probably dates back to the work of Soxhlet (1) / from 1886 to 1891. 
In general, however, the object has been partially or completely to 
sterilize the milk by the use of high temperatures rather than simply 
to pasteurize it at low temperatures. While the practice of steriliz- 
ing or partially sterilizing milk in bottles has been extensively prac- 
ticed in several countries in Europe, the pasteurization of milk in 
bottles has not been so common. 
i The figures in parenthesis refer to the list of citations to literature at the end of the 
paper. 
Note. — This paper is of interest to milk dealers, health officials, and all who have to do 
with the milk supply of cities ; it is suitable for distribution in all parts of the country. 
94289°— 15 1 
