Experimental cookery

Fat. Butter is preferable in cakes because of its flavor, the rich, full- flavored, but not rancid, being better than the mild. Oils and melted fats can be used in cakes, but the texture is not as good as when fats that can be creamed are used. Creaming is forming a foam by incorporating air bubbles in a fat by stirring. Creaming fat is somewhat similar to beating eggs or egg whites, in that the enclosed air later aids in leavening. Air is enclosed in the fat more rapidly after some sugar is added, hence creaming is usually done by adding the sugar to the fat, either gradually during the creaming process, or all at one time. The sugar adsorbs a portion of the fat on its surface and is suspended in the fat. If, as suggested in the chap- ter on meats, adsorption of fat at an interface renders it softer and more plastic than when not adsorbed at the same temperature, a suggestion is given for better creaming after the sugar is added. In addition the sugar crystals aid in supporting the fat in the walls around the air bubbles in much the same manner as the fat globules in whipped cream. See Fig. 31. For a fat to cream or form a foam it must have some body, for if it is too warm so that it is partially or entirely melted it does not cream. On the other hand, a fat that is hard and brittle and not plastic does not cream well. The hard fats like tallow with high melting points are not desirable in cakes. They do not cream well and on account of their hardness after the cake has cooled, they impart a firm, crumbly texture. Minard and Myers both found that the texture of the fat is important in relation to creaming quality and in obtaining velvety texture in cakes. By the rate of cooling a fat after it is melted, its texture can be controlled so that it is very waxy and firm, soft and smooth, or granular with a lot of 480 BATTERS AND DOUGHS separated oil. Minard found the very firm, waxy lard did not cream well. Myers found a soft, smooth lard creamed best, butter ranked second, and grainy or granular lard was poorest. Since any fat tends to become harder at low temperatures and softer at higher temperatures, there is a range at which each fat creams best. Martin used hydrogenated lard, Crisco, 44 lards of varying softness and firmness, and butter. The initial temperature of all the fats at start of creaming was 24° to 25 °C. All creamed fairly well at this temperature, though in general they tended to cream better at higher temperatures. In general the volume was decreasingly smaller in the order named. A low initial room temperature retarded creaming. Creaming tends to elevate the temperature of the creaming mass, probably from friction, though the butter usually shows an initial drop in temperature. For optimum creaming the firmer fats require a higher temperature than 25 °C. The hydrogenated lard creams well at 30°C. or above this temperature, creaming the best of any fat tried on hot days. Optimum creaming temperatures for fats com- monly used are 24° to 29°C. (about 75° to 85°F.). In the studies of fats in relation to their use in cake at Iowa State College a highly significant correlation between the volume of the creamed mixture and their tempera- ture has been obtained, which indicates the volume of the creamed mixture is related to its temperature, as expected.