THE WHIPPING QUALITY OF CKEAM. 
17 
ACIDITY. 
It has often been noticed that cream which is several hours old will 
whip better than fresh cream. Because of this it was believed that 
the small amount of acidity developed in the cream influenced its 
whipping equality. Also the idea is prevalent that adding a small 
amount of commercial lactic acid to the cream improves its whip- 
ping quality. In order to compare the effect of acidity with the 
effect of age, tests were made on cream representing age without 
acidity, acidity without age, and both age and acidity. The acidity 
was obtained both by the natural formation of acid and by adding 
lactic acid. 
The maximum acidity which cream may contain without acquiring 
a sour taste is about 0.3 per cent. It was found that increasing the 
acidity up to and including 0.3 per cent had no effect upon the quality 
of the whip. (See Fig. 14 and Table 8.) Increasing the acidity in 
excess of 0.3 per cent caused a slight decrease in the quality of the 
eo 
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23 
20 
/^ 
/O 
_^ . B 
.e .6d .7 .Z5 
Fig. 14. 
/='£/r' C£A/T O/^ /?C//?/rr 
-Effect of increase iu acidity on whipping quality of cream. A — B, cream whlcli 
gives a good whip ; A — C, cream which gives a very poor whip. 
whip until the acidity had increased to such an extent that the 
cream began to curdle, at which point the whipping quality increases. 
This was found to be true regardless of whether fresh or aged cream 
was used. 
It is therefore evident that increasing the acidity of cream will 
not improve its whipping quality, as it is necessary to increase the 
acidity to such an extent as to render the cream sour before it will 
have any effect. 
