Cake recipes are legion in number, but the underlying principles for making cakes containing a fat are similar, though some variation must be made for different recipes, depending upon the particular ingredients and their proportion.

Cakes containing fat may be divided into two classes. First, the pound cake type, based on the old recipe, which is one pound each of butter, sugar, eggs, and flour, and in which no baking powder or soda is used, the lightness of the cake depending upon the expansion of moisture from the eggs and butter and the air incorporated in creaming and in the beaten eggs. Second, the cup or layer cake types that contain rather small percentages of fat and sugar, in which the lightness depends largely upon added baking powder. Between these rich and lean type formulas are many transitions.

One desirable quality in cake is a certain texture, often called velveti-ness. Velvetiness implies softness to the touch, but to obtain this softness it is necessary to have a definite amount of moisture, else the texture is too dry or too soggy. However, the proportion of liquid is not the only factor in developing velvetiness; the proportion of other ingredients and how they are handled are also important. A good cake should have a fine, even grain, with thin cell walls, and should not be powdery or crumbly. It should have a good flavor.

Pans and preparation for baking. The cake tends to expand to a better volume if the sides of the cake pans are not greased. But a piece of wax or other suitable paper, cut to fit the bottom of the pan and greased on the side next to the batter, facilitates removal of the cake from the pan.

The depth of batter in the pan also influences the texture of the cake, so that if a finer, more velvety texture is desired, the size of the pan should be such that the batter is at least 1 inch or 1 1/4 inches in depth.

Another factor affecting the texture of the cake, and more than might be expected, is the slope of the sides of the pans, straighter sides resulting in better textures.

Baking cakes. Temperatures for baking. Cakes containing fat are baked over a wide range of temperature, from below 100° to over 210°

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Fig. 51. - The effect of baking temperature on the volume of plain cake, when three types of baking powder were used, sulfate-phosphate (combination), tartrate, and phosphate. (Stone) being used. For instance, fruit cake may be steamed at 100° or baked in the oven from below 100°C. to over 175°C.

No very definite information was available as to what temperatures were preferable for baking cakes when using one of the three common types of baking powder. Theoretically, it seemed possible that a powder that released its gas rapidly at room temperature should be baked at a higher temperature than a powder that gave off its gas more slowly. Stone investigated the effect of varying the baking temperature on the volume and scores for plain cake. She used Formula I, with flour reduced to 284 grams and the amount of baking powder found to be optimum by McLean, or

8, 10, and 12 grams of sulfate-phosphate (combination), tartrate, and phosphate, respectively. The cakes for any one series were always mixed together and the batter divided into five equal parts by weight. Hence, any variation in the volume, texture, velvetiness, and eating quality for a set of five cakes was caused by the baking temperature. The time of baking was necessarily shorter as the oven temperature increased. The cakes were

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Fig. 52. - The effect of baking temperature on the average cake scores for plain cake when three types of baking powder were used. (Stone) baked in loaf pans, one-fourth the recipe being used for each cake. The volume was determined by seed displacement. The effect of baking temperature on cake volume is shown in Fig. 51. For the particular formula and amount of baking powder used the optimum baking temperature for all three types of baking powder was 185°C. (365°F.).

The total scores, which were the sum of scores for texture, tenderness, velvetiness, and eating quality, were affected by the baking temperature. These results are shown in Fig. 52.

The texture and velvetiness of the cakes varied with the different baking temperatures. Heat penetration of the cake batter is of course slower at the lower temperatures. The cakes baked at the lower temperature had thicker cell walls, coarser, more harsh, less velvety texture, and were altogether less desirable. The small volume and poor texture at the lower temperature are undoubtedly caused by the cake batter's not coagulating quickly enough in relation to the rate of gas formation. In other words, as the gas formed the temperature was not high enough to coagulate the

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Fig. 53, - The effect of baking temperature upon the volume of a rich (Recipe A) and a less rich (Recipe B) chocolate cake. With exception of lowest and highest temperatures for Recipe B, each point on the graph is an average of scores of 5 judges for 12 cakes. (Rogosheski and Bernds) egg and flour proteins, with the result that more than the optimum amount of gas escaped and more than the optimum amount of agitation occurred within the cake before coagulation started. For, as gas is produced its expansion agitates to a greater or less degree the cake batter. And if this agitation is continued too long before the crumb is coagulated, coarse textures result. With increase in the baking temperature the eating quality improved, the texture became finer and softer, the volume greater. Above

185°C. the cake became more compact because the crust formed too rapidly, although the texture was still velvety.

Sugar content and baking temperature. It is known that sugar is a good peptizer of egg proteins and elevates the coagulation temperature of egg proteins. It is also possible that sugar may affect the coagulation temperature of the flour proteins. From a few isolated observations some evidence has accumulated indicating that the higher the sugar content the higher the baking temperature should be for cake. But the work has not progressed far enough at present to draw definite conclusions.