56 BULLETIN 642, U. S. DEPARTMENT OF AGRICULTURE. 
r 
samples of milk produced under dirty conditions were held at 15.5° C. 
(60° F.) and 21.1° C. (70° F.) and examined when fresh, and after 
12, 24, and 48 hours. 
From Table 27 it will be seen that 16 samples of milk pro- 
duced under clean conditions in sterilized utensils when fresh 
averaged 3,243 bacteria per cubic centimeter. After 12 hours at 
15.5° C. (60° F.) the average count was 4,056 and at 21.1° C. 
(70° F.) 19,312 bacteria per cubic centimeter. This shows an 
advantage of holding at the lower temperature which is more valuable 
when the milk is held for 24 hours, as the average count was then 
123,562 when held at 15.5° C. (60° F.) and 10,006,875 -when held at | 
91.1° C. (70° F.). After 48 hours the average count at both temper- 
atures was high, but the milk held at 15.5° C. (60° F.) was much 
~ lower. 
The samples of milk produced under dirty conditions in unsterilized 
utensils ranged from 10,900 to 2,210,000 when fresh and averaged 
707,761 bacteria per cubic centimeter. This high initial average count 
increased to 3,876,961 after 12 hours at 15.5° C. (60° F.) and te 
6,608,846 after 12 hours at 21.1° C. (70° F.). The counts were, of 
course, very high at later periods at both temperatures. 
TABLE 27.—Growth of bacteria in milk when held at 15.5° C.° (60° F.) and 
QEAZACLM AOC AR'S,- 
MILK PRODUCED UNDER CLEAN CONDITIONS IN STERILIZED UTENSILS. 
Held at 15.5° C. (60° F.) for— Held at 21.1° C. (70° F.) for— 
SampleNo.| Fresh. 
12hours. | 24hours. | 48 hours. 12 hours. 24 hours. 48 hours. 
‘eae aoa 1,800} 4 2,300 48,000 | 13, 200, 000 8,100 | 4,100,000 | 1,290,000, 000 
Sy Aaa, 1; 900 2000 56,000 | 16,500,000 | 23,100 | 26, 200, 000 |” 860, 000; 000 
ce el a 1,700 1, 100 55,000 | 38,000,000 | 13,600 | 23, 700, 000 | 2, 410, 000, 000 
Gale ep 3,100 1, 800 SALOU see 29,100 | 12,400,000 |... -......-._. 
Fete ek 11, 200 7,300 83,000 | 41,000,000 | 14,700 | — 4; 700, 000 | 1,340, 000, 000 
pee oes 7,900 8, 700 51,000 | 57,000,000} 37,000 | _ 8,200,000 | 1,810, 000, 000 ‘ 
[oe meee 1, 800 2; 100 78,000 |. 12, 900, 000 2,300 | 510,000 | * 81,000, 000 
Soe eel 700 1,700 28,000 | 4,800, 000 6, 1,880,000 | _ 82,000,000 
ore See 5,600 1; 900 23,000 | 20,100,000 | 25,200 | _5, 400,000 | 2,980; 000; 000 
Ta oe 1, 100 3,100 74,000 | 42,000,000 19,500 | 30,600,000 | ” 128,000,000 
ie AO 3, 400 100 38,000 | 14,100,000} 13,200 | 10,200,000 | 960, 000, 000 
er ae 1400 12 e018, 300 lias ~ S10), O00 tie aie 58,000 | 5,700,000 |......-...-.-. 
ee Abe Cae 3,100 2,200} 60,000 | 18,100,000 4,100 | 4,100,000 | 1,390, 000, 000 
[ae nis 1; 200 2,000} 261,000} 46,000,000 | 32,500 | 4, 920, 000 | 6, 400, 000, 000 
6a B84 3, 800 3,000} 112,000} 16,600, 000 5,800 | _ 6,000,000 | 6, 460, 000, 000 
‘Seamer Se 2; 200 2,300} 532140 O00) | eg tea. 16,000 | 11,500,000 |... -.222...... 
Average. 3,243 4,056 | 123,562 | 26, 176, 923 19,312 | 10,006,875 | 2,014, 692, 307 
MILK PRODUCED UNDER DIRTY CONDITIONS IN UNSTERILIZED UTENSILS. 
| I Sy Mie fd 10, 900 15,500 | USD OOS eee epee 58,.000°| “49, 000,000 |= = a ante 
2s i | 1,520,000 | 8,600,000 | 148,000,000 | 169,000,000 12,800,000 | 460; 000; 000 | 1, 780, 600, 000 
ie akin 1,880,000 | 8,700,000 | 154,000,000 | 840,000,000 17,600,000 | 960,000,000 | 7; 500; 000, 000 
6 ts | 1,020,000 | 5,400,000 | 22' 900,000 | 1,180;,000,000 | 8,200,000 | 630,000,000 |" ” 460,000,000 - 
op aa etcne: | 2;210,000 | 11,700,000 | 81,000,000 |” 28,000,000 | 13, 700,000 | 149,000,000 | 620, 000, 000 
bo 1,810,000 | 1,930,000 | 68,000,000 | 164,000,000 | 6,100,000 | 75,000,000 | 540,000,000 
jest a 330,000 | 4; 200,000 | 10,300,000} 113,000,000 | 10,200,000 | 37,000, 000 | 1,360,000,000 ~* 
fee 159,000 | 1,210,000 | 22'600;000 | 110,000,000 | 2'830,000 |............. 350, 000, 000 
on A Be 96,000 | 1,310,000 | 29,400,000 |............... | 10, 400, 000 | 114,000,000 |.............. 
Ws en Ss 37,000 | 560,0000 | 43,800,000 | 212,000,000 2;360,000 | 26,000,000 | 1,840,000, 000 
i a 18,000} 180,000 | 47,200,000 | 100,000,000 |. 1,370,000 | 96,000, 000 | 1; 500, 000, 000 
Rie Sar oe 12,000} 24,000} 1,480,000} 45,000,000 |” 99,000 | 32,000, 000 | 2,080, 000, 000 
ig ee 28, 000 71,000 |- 2,300,000 |............,.- 198,000 | 35,000,000 |.............. 
Average. 707,761 | 3,376,961 | 48,550,923 | 296, 100, 000 | 6,608, 846 | 221, 916,666 | 1,853, 000,000 
