56 PASTEURISATION OF MILK AND CREAM. 
~ 

Th-ckness of Cream on Milk wx quart bottles. 






- | ° . 
Time of ob- Inches of cream on Pasteurised Milk. 
a Inches of 
servation pee 
Date. after pas- 
mieesaks normal , 5 : 
eurisation milk. | 155 F. for 140 F. for | x40 F. for 
(hours). 15 min. 15 min 30 min. 
, 20 2 fo) 2 2 | a 
4 April26 - . - 
4 48 — 14 dim 2 12 1 — 
[ 6 14 fo) 613 «13 — 
f April 27 . - - 4 22 12 o 1 12 2 — 
| . 
[ 46 12 14 dim 13 13 2 — 
( 6 3 ° 1% 0613 «oy ae 
| 
} April2g - - - < 20 13 ° iy Is If — 
| 100 = 13 dim — — 
f 21 13 fo) 1 3 a 
q May r- - 
3 1 1 
rt 45 13 fo) pie Tige Diss — 
{ 21 12 ° — 13 3 x: 
g May 2- : : 2 J | 
; \ 72 12 | faint = rg 313 xz 
| 
§ May 3- - = - - 20 Tz fo) _ 3 3 12 
| 20 12 ° — 13 of 2 
H May 4- - - - 4 100 -- dim —_ 2 2) 2 
| 125 = 2 — Veet ec 
5 


The foregoing results are held to show that pasteurising at 
155 F. and subsequent cooling to 50 F. so changes the 
character of the milk that the creaming of the same is not 
only greatly retarded but actually lessened in quantity. The 
cream line in the pasteurised milk was, it appears, invariably 
less sharply defined and could not readily be perceived until 
the milk had remained in cold water for about 48 hours. In 
the case of the milk pasteurised at 140° F. for either 15 or 30 
minutes the cream is stated to have risen quickly and as 
completely as in normal milk, while the close uniforiity of 
the results obtained with the triple samples at this 
tempsrature shows that the creaming of such milk was 
practically uninjured. 
In this connection the authors observe als“ that in samples 
pasteurised at 140° F. for 60 minutes the creaming property 
was also normal, and this they regard as an indication that 
the period of exposure in pasteurisation has no material 
