2 BULLETIN 1161, U. S. DEPARTMENT OF AGRICULTURE. 
EXPERIMENTAL WORK. 
TREATMENT OF MIXES AND CONDITIONS OF WHTPPING AND FREEZING. 
The size of each mix made for these experiments was 25 pounds. 
The treatment given to each set of mixes was always the same, although 
it was purposely varied on different sets in the same experiment. 
Usually one set of mixes was sufficient for at least two days' sales. 
The ice cream was sold to department employees during the noon 
lunch period, between 12 and 12.30. 
Some mixes were pasteurized and aged for from 24 to 96 hours. 
Others were homogenized and aged for varying periods before freez- 
Fig. 1. — Ice-cream laboratory where exper 
merits are made under conditions similar to those in commer- 
cial manufacture. 
ing, while some sets of mixes were frozen a few hours after they were 
made up. The temperature at which each set of mixes was aged 
also varied. 
The whipping and freezing was done in a horizontal 24-quart brine 
freezer. The brine temperature varied from 3° F. on some days to 
15° F. on other days, with the speed of the freezer kept fairly con- 
stant. The ice cream from each mix was hardened in a 3-can cabinet 
packed with crushed ice and salt. The amount of inflation (swell) 
obtained in the different grades of ice cream ranged from 42 to 93 
per cent. 
The ice cream was always hardened in and dispensed from the same 
cabinet, so that the temperature and other conditions which might 
affect it were practically alike during the time it was offered for sale. 
