PASTEURIZING MILK. 
13 
Table 2. — Comparison of bacterial reductions in milk pasteurized in unsteamed 
bottles and in pasteurized milk bottled while hot in steamed bottles. 
Raw milk 
(bacteria 
per c. c). 
Milk pasteurized at 145° F. for 30 minutes. 
Sample No. 
Hot pasteurized milk 
in hot steamed bot- 
tles. 
Milk pasteurized in 
washed but un- 
steamed bottles. 1 
Bacteria 
per c. c. 
Percentage 
reduction. 
Bacteria 
per c. c. 
Percentage 
reduction. 
2 
58,000 
63, 000 
5,100,000 
580,000 
5,900,000 
99, 000 
7,400,000 
191,000 
14,100,000 
24,700 
75,000 
126, 000 
4, 100, 000 
76, 000 
8, 100, 000 
18, 900 
24,000 
28,300 
80, 000 
160,000 
151,000 
81,000 
1,160 
220 
8,400 
8,300 
6,000 
610 
6,300 
2,000 
7,000 
4,550 
3,000 
1,440 
2,470 
1,400 
1,620 
760 
800 
7,050 
1,360 
1,830 
3,200 
6,800 
98.00 
99.65 
99.83 
98.57 
99.90 
99.38 
99.91 
98.95 
99.95 
81.58 
96.00 
98.86 
99.94 
98.16 
99.98 
95.97 
96.66 
75.09 
98.30 
98.86 
97.88 
91.60 
1,630 
1,070 
11,800 
8,000 
15,600 
980 
7,100 
7,600 
14,200 
5,780 
28,000 
1,720 
2,410 
3,550 
1,660 
710 
10, 900 
23,300 
2,010 
29,500 
12,500 
9,800 
97.18 
3 
98.30 
4 t 
5 
99.76 
98.62 
6. 
99.74 
7 
99.01 
8... 
99.90 
9 
96.02 
10 
11 
99.89 
75.59 
12 
13 
62.66 
98.63 
14 
99.94 
15 
95.32 
16 
99.98 
17 
96.24 
18 
50.41 
19 
17.67 
20 
97.48 
21 
81.56 
22 
23 
91.72 
87.90 
Average 
2,115,268 
3,467 
96.50 
9,083 
88.34 
1 Bottles were washed clean in hot water, but not steamed, before they were filled with raw milk. 
The results of the bacteriological examinations are shown in Table 
2. It will be seen that the average count of the raw milk was 2,115,- 
268 bacteria per cubic centimeter. After being pasteurized in bulk 
and bottled hot in hot steamed bottles the average count was 3,467 
bacteria per cubic centimeter, while the average count when pas- 
teurized in bottles was 9,083 bacteria per cubic centimeter. Compar- 
ing the percentage of bacterial reductions, it will be noted that the 
average reduction of the milk bottled hot was 96.50 per cent and only 
88.34 per cent in the milk pasteurized in bottles. In 19 of the 22 
samples the bacterial count was lower in milk pasteurized in bulk and 
bottled hot. In many cases the count was much lower, as may be seen 
by comparing samples 4, 6, 7, 12, and 18. This difference is par- 
ticularly striking in sample 21, in which milk pasteurized in bulk 
and bottled hot showed a count of 1,830, and some of the same milk 
pasteurized in a bottle for the same time and at the same temperature 
contained 29,500 bacteria per cubic centimeter. 
In the belief that this marked difference might be due to the fact 
that the bottles were steamed in the first case and unsteamed when 
the milk was pasteurized directly in bottles, another series of samples 
was pasteurized in which both bottles were steamed for two minutes 
