24 BULLETIN" 240, U. S. DEPARTMENT OF AGRICULTURE. 
A study of the results in Table 8 shows that the cream-line forma- 
tion is a variable factor. Sometimes it was reduced by pasteuriza- 
tion even when the milk was cooled to low temperatures within 15 
seconds, and at other times there was no difference. In some ex- 
periments the cream line was slightly less on milk cooled slowly and 
again it was slightly higher. Throughout the experiments on pas- 
teurized milk bottled hot in ordinary milk bottles a good clear cream 
line was obtained. When milk stood at temperatures above 80° F. 
for several hours without agitation some of the melted butter fat rose 
to the top of the bottle and en cooling formed a small lump of 
butter. This was not observed, however, when the cooling process 
was begun immediately after bottling, even though the cooling was 
gradual. 
As to the effect on the flavor of the milk, it may be said that there 
was no more effect than that produced by milk pasteurized and 
cooled rapidly, except in instances where the milk was held above 
100° F. for several hours, as was the case in some of the experiments, 
in which a slightly more pronounced cooked taste was noticeable in 
the milk. 
In this connection attention is called to the fact that these results 
hold only for milk pasteurized at 145° F. and can not be applied 
where higher temperatures might be used, as it is possible that with 
higher temperatures different results might be obtained. 
BOTTLES TO BE USED IN THE PROCESS OF BOTTLING HOT 
PASTEURIZED MILK. 
It is obvious that a quart bottle filled with milk at 145° F. will not 
contain a full quart when the milk has cooled to 50° F., owing to the 
contraction during cooling. Several experiments which were made 
to determine the loss in volume during cooling showed a shrinkage 
in a quart bottle which averaged about 18.40 cubic centimeters. As- 
suming a quart of milk to be 946.35 cubic centimeters, that volume at 
145° F. would therefore contract to about 927.95 cubic centimeters 
when cooled to 50° F. If a quart bottle is filled with milk at 145° F., 
it will be 18.40 cubic centimeters, or 0.62 of an ounce, short of 1 quart 
when cooled to 50° F. To overcome this shortage bottles of a slightly 
larger capacity should be used when filled with milk at 145° F. A 
bottle should be of sufficient size to hold 1 quart of milk measured 
at 50° F. which has been heated to 145° F. 
PROCESS OF BOTTLING HOT PASTEURIZED MILK UNDER COMMER- 
CIAL CONDITIONS. 
Having discussed the various steps in the process of bottling hot 
pasteurized milk, the possible application of this process of commer- 
cial conditions may be outlined. 
