WHIPPING CREAM 21 



In the frozen cream studies a batch of cream was prepared according to the 

 standard procedure as given under experimental methods. Immediately after 

 standardization the cream was given the following treatments: 



1. Control — pasteurized cream, not frozen. 



2. Frozen 50 percent solid, then pasteurized. 



3. Totally frozen, then pasteurized. 



4. Pasteurized, then frozen 50 percent solid. 



5. Pasteurized, then totally frozen. 



The cream was frozen in one-gallon ice cream cans placed in brine at approxi- 

 mately 0° F. Immediately after freezing, the cream was thawed slowly by 

 placing the cans in a water bath at 70° F. It was then pasteurized, cooled, 

 aged, and whipped according to standard procedure. 



The results are given in Table 12 and Figure 19. Freezing cream 50 percent 

 solid, either before or after pasteurization, had no significant effect on the 

 whipping qualities of the cream. Total freezing of cream before pasteurization 

 destroyed the whipping properties of the cream, while total freezing of the 

 cream after pasteurization was only slightly detrimental to the whipping prop- 

 erties. The results on the effect of partly frozen milk as well as those obtained 

 with cream frozen before pasteurization are in close agreement with those ob- 

 tained by Baldwin and Combs (6). 



These results have a practical significance because they indicate that if the 

 cream should be totally frozen while in the hands of the producer, most of the 

 whipping properties would be destroyed. If the cream should be frozen 

 after it has been processed, for instance while standing on the customer's door- 

 step, then the whipping properties would be only slightly damaged. 



Effect of Feed 



The Animal Husbandry Department of this station conducted an investi- 

 gation in which tankage was compared with a soybean - cottonseed ration for 

 milk production. Since the theoretical explanation of cream whipping is con- 

 cerned with the protein membrane surrounding the fat globules, it seemed 

 desirable to check the whipping ability of the cream produced while the two 

 sources of protein were being compared. The entire production of each group 

 of twelve cows for one milking was kept separate on two occasions, and a 

 representative portion of each lot was separated and standardized to 32 per- 

 cent fat. The cream was whipped and the results are given in Table 13. The 

 results show that the source of food protein, namely animal and vegetable, 

 had no significant effect on the whipping ability of the cream. 



