12 BULLETIN 240, TJ. S. DEPARTMENT OF AGRICULTURE. 
for 30 minutes and then drawn off while hot through the outlet pipe 
into hot milk bottles which had been steamed 2 minutes. As stated 
before, this method of bottling milk while hot was suggested in Cir- 
cular 184 of the Bureau of Animal Industry (5). but the suggestion 
then was to bottle hot milk in cold bottles. In this work it seemed 
advisable to bottle directly into hot bottles, as it makes it possible 
to steam the bottles and fill them before infection can take place. 
Also, this method eliminates the possibility of breaking bottles. 
"While working on this process of bottling milk hot it has been found 
that a similar process was apparently patented several years ago. but, 
so far as known, it has never been used to any extent. This process 
as described by de Schweinitz (7) consisted in pasteurizing the milk 
at temperatures from 160° to 180° F. and placing it while hot in a 
sterilized milk jar or fruit jar with a flap top. Special paper caps 
were used. The jars of milk were cooled by being placed in troughs 
of iced water. 
COMPARISON OF BACTERIAL REDUCTIONS IN MILK PASTEURIZED 
IN BOTTLES AND MILK PASTEURIZED IN BULK AND BOTTLED 
WHILE HOT. 
Since it has been shown earlier in this bulletin that excellent bac- 
terial reductions may be obtained by pasteurization in bottles, a 
question of great importance arises as to whether or not as good 
results can be obtained by pasteurizing milk in bulk and bottling 
while hot. 
A series of 22 samples of raw milk was pasteurized by both proc- 
esses at 115° F. for 30 minutes. Part of the milk was pasteurized in 
bulk in the pasteurizer shown in fig. 7 and bottled hot in hot bottles 
which had been previously steamed for two minutes. In all these 
experiments the bottles were capped with ordinary paper caps, no 
precautions being used in capping by hand. Another portion of the 
same raw milk was pasteurized in bottles. Both samples of pasteur- 
ized milk were examined bacteriologically while hot in the bottles. 
In the first series the bottles in which the milk was pasteurized 
directly were washed with hot water and washing powder imme- 
diately before they were filled with raw milk. 
