THE CREAMING ABILITY OF MARKET MILK 
13 
Table 11. — Effect of various storage temperatures on the rapidity of cream- 
ing — Laboratory experiment 
All samples cooled to 
42° 
F.] 
Character of milk 
Stor- 
age 
tem- 
per- 
ature 
Cream volume after number of hours indicated 
Test 
No. 
Vi 
1 
IK 
2 
lYi 
3 
m 
4 
6 
8 
20 
1 
o p 
66 
54 
42 
66 
54 
42 
66 
54 
42 
66 
.54 
44 
63 
53 
42 
66 
53 
42 
66 
53 
42 
66 
53 
42 



























15 
15 
17.5 
14.5 
13.5 
15 
.5 
3 
3 
7 
3 
2 
17 
17 
18 
14.5 
14 
14 
1 
2 
2 
12 
12 
18 
15 
15.5 
17.5 
14.5 
14 
15.5 
4 
5 
6 
11 
10 
9 
17 
17 
18.5 
15 
15 
15.5 
3 
4 
4 
13 
13.5 
18.5 
18 
17.5 
18. 5 
14.5 
14.5 
16 
6 
8 
8 
11 
11 
11.5 
17 
17.5 
19 
15 
16 
16.5 
5 
7 
7 
13 
14 
19 
18 
17.5 
18.5 
14.5 
15. 
16 
"11"" 
11.5 
12 
16 
17 
18 
15 
15.5 
16.5 
6 
8.5 
7.5 
13 
14 
19 
17 
17.5 
18.5 
14.5 
15 
16 
7 
8 
9 
11 
11.5 
12 
16.5 
16.5 
18 
15 
15.5 
16.5 
6 
8.5 
9.5 
13 
14 
19 
17 
17.5 
18 
14.5 
15 
15.5 
_„„ 
11.5 
12 
16 
16 
17.5 
15 
15.5 
16.5 
7 
9.5 
10 
12.5 
13.5 
18.5 
16. 5 
17 
17.5 
14.5 
14.5 
15.5 
7 
8.5 
9.5 
11 
11.5 
12 
16 
16 
17.5 
15 
15.5 
16.5 
7 
9.5 
10 
12.5 
13 
18 
12 
13 
15 
16 
14.5 
14.5 
11.5 
1 
Pasteurized at 143° 
to 142° 
12 
16.5 
14 
1 
Pasteurized at 145.5° 
to 145°. 
14 
15.5 
13 
Pasteurized at 148° 
to 147° 
13 
14.5 
1 

6.5 
9 
8.5 
9.5 
11 
2 
11 
11.5 
12 
16 
16 
17 
15 
15.5 
16 
11 
11.5 
12 
15 
15 
17 
14 
14 
15.5 
10 
10 
10. 5 
2 
Pasteurized at 143° 
to 142° 
11.5 
11. 5 
13 
2 
Pasteurized at 145.5° 
to 145°. 
14 
15.5 
12 
2 
Pasteurized at 148° 
to 147° 
13.5 
14.5 
8.5 
10.5 
11 
RAPIDITY OF CREAMING OF RAW AND PASTEURIZED MILK 
In Table 12 are given the results of laboratory tests to show the 
rapidity of creaming of raw and pasteurized milk; all samples 
were cooled to 42° F. and stored at 48°. It will be noted in this 
table as well as in Table 11 that the pasteurized samples, excepting 
those pasteurized at 147° to 148° F., showed a greater cream volume 
after 1 or 2 hours than did the raw milk, and also greater than the 
same samples showed after 20 hours. 
In other words, the tests indicate that pasteurized milk, especially 
when it is heated to not over 143° F. for 30 minutes, may have an 
inflated cream volume after about 2 to 5 hours, but that this gradu- 
ally contracts as the storage period is prolonged. 
The fresh raw milk showed a greater cream volume after 2 or 3 
hours than it did after 20 hours, but in the old raw milk the maxi- 
mum cream volume appeared after storage for 20 hours. These 
tests have an important bearing on experimental work to determine 
the effect of pasteurization on the creaming ability of market milk. 
In case the samples are examined after 4 or 5 hours the pasteurized 
milk will in nearly all cases show a greater cream volume than the 
raw milk. In the case of tests Nos. 2 and 3 the old raw milk showed 
an abnormally small cream volume for the butterfat contained, and 
for that reason the pasteurized samples had greater cream volumes 
than the raw. excepting those pasteurized at 147° to 148° F. 
