^"S!? 



ICE-CREAM AND ICES 633 



infection. Pasteurized cream is held in a cool place for at least 

 twelve hours, or longer, before it is used. During this period 

 the viscosity, which is largely destroyed by pasteurization, reap- 

 pears. Viscosity is a vital quality of cream for ice-cream making, 

 as without it the overrun is difficult to obtain. 



Ice-cream manufacturers give considerable attention to ob- 

 taining a product which has the right "body" and "texture." 

 These terms are frequently confused and are defined by Washburn 

 as follows: "The words 'body' and 'texture' are used in ice-cream 

 making to mean two quite different things. Body is synonymous 

 with structure or substance. It refers to the entire mass as a unit. 

 Texture, on the other hand, has to do with the finer make-up of 

 the article. The structure of table linen, for instance, consists 

 of a smooth fibrous piece of cloth. Its texture, on the other hand, 

 indicates a lot of closely woven threads. The one has to do with 

 the mass characteristics, the other with the arrangement of the 

 particles." 



The body of ice-cream is conditioned chiefly by the milk solids. 

 It is, therefore, the practice of many manufacturers to add evapo- 

 rated milk to the mixture, by which process the smoothness and 

 food value of ice-cream are incidentally and materially increased. 

 Sometimes wheat flour, rice flour, or cornstarch are added, espe- 

 cially when the cream is poor in fat. When rich cream is used 

 such additions offer no advantage. 



Gelatin is also very generally used to improve the body of 

 ice-cream. 



The aim of ice-creani manufacturers is to sell a product which 

 is firm and mellow. 



The texture of ice-cream should be smooth and there should 

 be no ice crystals present. The manner of freezing is important 

 in this respect, as rapid freezing produces crystals, while slow 

 freezing with violent agitation causes the product to be smooth 

 and free from crystals. The agitation or "whipping" incorpor- 

 ates a large amount of air with the mixture, frequently as much 

 as 33 to 40 per cent. The addition of gelatin or such substances 

 as gum tragacanth, eggs, etc., insures the stability of the texture 

 and prevents the formation of crystals when the ice-cream stands. 

 These substances are known as "stabiHzers," "binders," "fillers," 

 and "colloids." 



For ordinary creams gelatin is probably used more than any 

 other substance as a filler. A very small amount is needed. If 

 a good quality of gelatin is used, 4 ounces is a suflficient addition 

 to 10 gallons of ice-cream mixture. The product is rendered 

 smooth and does not become sandy or have a crystalline texture. 

 Large quantities of gelatin are to be avoided, since they make the 



