Experimental cookery

Ice cream made from homogenized cream is smoother and has smaller crystals. In homogenization of the cream the fat globules are broken up. As the size of the globules is decreased the surface area increases. The fat globules are surrounded by a film of protein. After homogenization, owing to the increased surface, a larger amount of protein is held in the film around the fat particles. The increase in the number of the fat globules and the protein held in the film increases the viscosity of the cream. After homogenization the cream should not be agitated. The higher the pressure used during homogenization, the greater the viscosity obtained in the cream. With homogenized cream, less fat and less milk solids not fat can be used and a texture obtained that is as good as that from an unhomogenized cream with higher fat content and with higher milk solids. Pasteurization. Pasteurization decreases the viscosity of the cream. Cream needs to be aged after pasteurization before it is used in ice cream. HOME-MADE ICES AND SHERBETS 95 The Use of Gelatin in Ice Cream Gelatin is used in ice cream to prevent the formation of coarse crystals, during softening and hardening of ice cream packed in an ice-and-salt mixture, while it is held for selling. Holdway and Reynolds have demon- strated that gelatin in ice cream prevents it from losing its shape while it is melting. Sugar in Ice Cream Sugar is used for sweetening the ice cream. It increases the total solids, thus improving the body. Too high a percentage lowers the overrun and gives an ice cream that is too sweet. Sucrose is used in ice cream. Other sugars may be used, such as invert sugar from sucrose, corn sugar, and levulose. Since the commercial levulose is too expensive, honey may be used. Corn sugar or dextrose is not so sweet as sucrose and therefore can be substituted successfully for only about 25 to 35 per cent of the sucrose in ice cream. Making Ice Cream in Refrigerators at Home Ice cream may be held as well as frozen in mechanical refrigerators. When frozen in them the ice cream often does not have a good texture because it is not stirred sufficiently during the freezing process. Some units have been made that stir the mixture while it is freezing but they are not common. However, quite acceptable ices, sherbets, and even ice cream may be made by adding substances, such as egg white or whipped cream, that tend to delay crystal growth. Beaten egg white is best for ices and sherbets, because this product is more typical of an ice or sherbet texture than the product formed by adding rich whipped cream. A good time to add the beaten egg white to ices is just as the mixture starts to freeze, for the stirring at this time aids in the formation of more nuclei. Whipped cream may be added before or after the mixture is placed in the refrigerator tray, depending on the type of product to which it is added. Ice-Cream Improvers The published results of Isenberg and Baer, on the use of ice-cream improvers in commercial products, indicates that they would be of prac- tically no benefit in home-made ice cream. Home-Made Ices and Sherbets Ices and sherbets have a lower freezing point than ice cream, for they usually contain a greater quantity of sugar. The use of gelatin and egg 96 FREEZING