2 BULLETIN 1075, U. S. DEPARTMENT OF AGRICULTURE. 



There are many factors which influence the whipping quality of 

 cream, but it is impossible to discuss them in the order of their im- 

 portance, because one factor is sufficient to render what would other- 

 wise be an excellent whipping cream useless for whipping purposes. 

 The most important factors are : Kind of cream, age, butterfat con- 

 tent, and temperature. 



EXPERIMENTAL PROCEDURE. 



The same method of whipping was followed throughout this ex- 

 periment. One hundred cubic centimeters of cream were placed in a 

 600 c. c. beaker, which was put in a dish and surrounded with ice 

 to keep the temperature 45° F. or below (except when determining 

 the effect of temperature upon the whipping quality). The cream 

 was then whipped with an ordinary " Dover " egg beater. As this 

 beater is operated by hand, it is impossible to determine the speed 

 accurately. Approximately, however, 200 revolutions per minute of 

 the handle were made, which gave a speed of 1,000 revolutions per 

 minute of the whipping blades. All factors relating to the method 

 of whipping, quantity whipped, and temperature remained constant 

 throughout the experiment, so that any change in the whipping qual- 

 ity was due to some other factor or factors — not to a change in the 

 method of procedure. 



The acidity of the cream was determined by titrating with tenth- 

 normal alkali, phenolphthalein being used as the indicator. 



The time recorded in the various tables is the time of continuous 

 whipping required to obtain the maximum whip, except in cases 

 where the cream failed to whip ; in such cases the maximum stiffness 

 remained the same, or so nearly the same that it was impossible to 

 determine when the maximum was reached. In all cases the cream 

 was whipped for a longer time than recorded, in order to be certain 

 that the maximum whip had been obtained. 



METHOD OF COMPARING STIFFNESS OF WHIPPED CREAM. 



In order to determine the relative stiffness of different samples of 

 whipped cream it is necessary to have some device that will measure 

 comparative stiffness. The methods usually employed for measuring 

 viscosity are as a rule too complicated to admit of practical appli- 

 cation. 



The following simple method will enable any one to test the stiff- 

 ness of different whipped creams very satisfactorily. It is, however, 

 purely a relative measure intended for direct comparison of differ- 

 ent creams and the determinations are not comparable with those 

 obtained on the basis of other standards. 



The apparatus is in the form of a balance. (Fig. 1.) The right 

 arm of the balance is divided into 60 equal spaces, zero being at the 



