CHAPTER VIII 
PASTEURIZATION 
Pasteurization of milk consists in heating the milk 
at various temperatures below boiling for a variable 
period of time. The term pasteurized milk is very indefi- 
nite in its meaning because the process is not always car- 
ried out in the same manner, but since 1913, when the 
Commission on Milk Standards of the New York Milk 
Committee published its second report, there has been 
more uniformity in this country than formerly with re- 
gard to temperature and time of exposure, state and 
local authorities having very generally accepted the 
standard adopted by the Commission. This standard 
specifies 140 to 155° F. (60 to 68° C.) as the minimum 
temperature at which the milk shall be heated, the mini- 
mum period of exposure to be 20 minutes at 140° F. 
(60° C.), with one minute less for each degree of tem- 
perature above 140° F. But, at the same time, in order 
to allow for the variations in temperature and holding- 
time which may occur under commercial conditions, the 
Commission recommended that the milk be heated to 
at least 145° F. (62.8° C.) for at least 30 minutes. In 
Europe, pasteurized milk is usually milk which has been 
heated for a few moments at 176° F’. (80° C.) or above, 
although within recent years the method of heating the 
milk at a lower temperature for a longer period has 
been adopted to some extent. 
When the first commercial milk pasteurizer was in- 
troduced into this country in 1895, pasteurization was 
recommended to milk distributers as a means of pre- 
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