The cooking temperature and the length of time of cooking. In general, the longer the time of cooking the greater the fat absorption. Table 63 shows rather typical results.

Effect of the Cooking Temperature and the Length of Time of Cooking

Upon Fat Absorption in Doughnuts. Dough Mixed 80 Strokes with

Wooden Spoon. Six Doughnuts in Each Lot

The results in Table 63 show less fat absorption at the higher temperatures. Sometimes the differences are not so great. Extreme temperatures were used in these doughnut experiments. In ordinary cooking as low a temperature as 155°C. would not be used, for the doughnuts would require too long a time to brown. Nor would the high temperature be used, for the doughnuts become too brown in a very short time. The doughnuts cooked for 2 minutes are not so brown as those cooked 4 minutes. Those cooked at 155° to 160° are very pale in color; those at 195° to 200°, except the ones cooked 2 minutes, are too dark in color. Usually the preferable color is obtained by cooking at 175° to 180° for 3 or 4 minutes. The doughnuts cooked at the highest temperature usually have a smaller volume than those cooked at 175° to 180°, probably because the crust hardens quickly at the higher temperature and thus prevents expansion. This would be one factor that causes decreased fat absorption at 195° to 200°, as the doughnuts would have less surface area.

Letting the dough stand before frying. If the dough is allowed to stand a short time before frying the amount of fat absorbed while cooking is usually lessened, but sometimes just the opposite happens, and a larger quantity of fat is absorbed. The volume of the cooked doughnuts is usually greater after the dough is allowed to stand a short time. This would tend to cause greater fat absorption on account of greater surface area.

Effect of variation of proportion of ingredients in the recipe.

If different doughnut recipes are compared, the proportion of ingredients will be found to vary somewhat. One recipe may contain a larger proportion of sugar, another of fat. This variation of proportion of ingredients will influence the percentage of fat absorbed.

Effect upon Fat Absorption of Increasing the Sugar in the Recipe from 1 to 1 1/2 Cups. Cooked 3 Minutes at 175° to 180°C.

Sugar. When the sugar in the regular recipe is increased from 1 to 1 1/2 cups the dough is quite sticky and difficult to handle. The dough appears as if it contained a thick sirup. The fat absorbed during cooking is decidedly increased. If the dough is mixed longer it becomes less sticky and the gluten better developed, and fat absorption is decreased. The result upon the texture is similar to that obtained when sugar is increased in cake. The dough requires more mixing than the regular recipe to obtain good doughnuts. The best texture is usually obtained with 180 to 200 strokes.

Fat. When the fat in the recipe is increased the fat absorbed during cooking is increased. When the fat in the recipe is increased, the extent of mixing does not affect the fat absorption so much, i.e., fat absorption does not decrease so rapidly with longer mixing as in the regular recipe. There is also the possibility of variation of amount of fat absorbed, when different kinds of fats, such as butter, Crisco, or lard, are used in the dough. When flour is increased, which the homemaker tends to do because increased fat gives a softer dough, the fat absorption is not always increased by doubling the fat in the recipe.

Eggs. When the number of eggs in the recipe given in the outline is increased from 2 to 3, with no other change, the dough is softer and more sticky, because of the moisture content of the egg. This tends to cause increased fat absorption. The coagulation of the increased egg in the crust tends to decrease the fat absorption. The final result is the sum of these antagonistic effects. Sometimes one factor and sometimes the other predominates. In making doughnuts the tendency would be to add more flour to roll the dough more readily, and this would decrease the fat absorption. Other factors in addition to the two mentioned above will also affect the amount of fat absorbed. These include surface area and the extent of mixing. The volume of the doughnuts with increased egg may be larger than the volume of those in the regular recipe, giving a greater surface area for absorption of fat. Doughnuts made with increased egg may contain tunnels, and there is a tendency for them to be tough.