860 EXPERIMENT STATION RECORD. 



The body (general firmness) and texture (smoothness) of ice cream are 

 influenced by a number of factors, such as the age and Idnd of cream used, the 

 amount of milk fat or other millv solids in the mixture, and the kind and 

 amount of filler used. In order to secure good body and texture the cream 

 should be aged from 24 to 48 hours at a low temperature before being frozen. 

 If the cream is properly aged the product retains good body and texture for a 

 much longer period than otherwise. Experiments with creams having percent- 

 ages of milk fat varying from 8 to 30 per cent showed that ice cream made from 

 cream having less than 18 per cent of fat was weak in body and poor in texture. 

 The thinner the cream used the more filler was needed to accomplish the desired 

 results. 



The time of freezing and the speed of the freezer is important. A mixture 

 frozen too rapidly was coarse in texture and weak in botly, while if the speed 

 of the dasher or disks was too low the cream was not whipped to the proper 

 consistency and smoothness. 



Since an excessive overrun results in a product of poor quality it should be 

 avoided. A number of factors which influence overrun were studied, and these 

 showed in general that by careful standardizing of the ice cream " mix " and 

 by regulating the freezing operation it was possible to obtain a uniform overrun 

 from day to day. A raw cream produced a higher overrun than a pasteurized 

 cream. Aging a pasteurizetl or homogenized cream made a higher swell pos- 

 sible. Rapid freezing resulted in a lower overrun than when sufficient time 

 was given to properly whip up the mixture. The kind and amount of filler did 

 not seem to affect the overrun. A high swell resulted in an open-textured, 

 light, foamy ice cream, and such a product was of poorer quality than one with 

 less overrun. Because the amount of overrun affects the weight of ice cream, 

 the nutrients in a given volume will also be affected ; a high overrun ice cream 

 contains less nutrients than a lower overrun product. 



The flavor of ice cream is influencetl by several factors, among thera quality 

 of flavoring materials, richness of cream, taints of cream, kind of cream, filler, 

 and storage of the finished product. A pure extract of vanilla will produce a 

 more pleasant flavor than cheap, imitation compounds. The natural fruit 

 flavors are more desirable than the cheaper grade of extracts. An old. taiuteil, 

 partly sour cream can not be made into a good ice cream. An excessive use of 

 a low grade gelatin or ice-cream powder always can be detected in the flavor. 

 Considerable data are also given regarding the processes of freezing; the tem- 

 perature during freezing; packing; and testing. A few simple formulas are 

 given together with suggested score cards for judging ice cream. It is stated 

 that creameries and milk plants can profitably make ice cream without much 

 additional equipment, and if advantageously located they can install an equip- 

 ment for manufacturing ice cream for about .$.tOO. 



The manufacture of ice creams and ices, .7. H. Franosex and E. A. Mark- 

 ham (Xcw York: Orange Judd Co., 1915, pp. A'/V+Jio. figs. 10<?).— The chap- 

 ters included in this book are the cream sui)ply ; the bacteriology of ice cream ; 

 the care of milk and cream at the factory ; condense«l milk, milk powder, and 

 homogenized cream ; stabilizers ; flavoring ; standardizing the ice cream mix- 

 ture ; preparing the ice cream mixture ; classiflcation of ice cream ; ice cream 

 formulas ; water ices and sherbets ; fancy molded ice creams ; the freezing 

 process; refrigeration; the economical operation of the refrigerating plant; 

 .scoring ice creams and ices; the ice cream factory, its location and equipment; 

 factory nianagonient ; by-products and side lines ; and ice cream as a side line 

 in the local creamery. 



