FoodNet

Experimental cookery

1932

Page 410

Presented as published in 1932. Historical recipes may not meet modern food-safety standards. Cook from the modern interpretation, not the original instructions.
Effect of alkali upon texture of gingerbread. Soda is used with the molasses or sorghum for leavening in gingerbread. Excess soda is often used. For this reason gingerbread offers an excellent opportunity to observe the effect of an excess of alkali upon the texture and the flavor of a batter. The gluten of bread dough becomes more elastic, more extensible and more soluble, i.e., dispersion is increased, as the acidity of the dough increases. This results in a greater volume of the bread until a degree of acidity is reached at which the gluten becomes too tender to stretch as the gas forms. At this point some of the gluten films break and the cell walls collapse. As the acidity is increased, more and more cells collapse and a bread with a thicker, coarser texture is produced. The gluten also becomes more elastic and more extensible with alkalies. As the alkalinity is increased, the solubility or dispersion of the gluten increases more rapidly than on the acid side. Thus with an alkaline reaction the cell walls become more tender and collapse more quickly than with an acid reaction. This with the larger proportion of liquid gives the typical coarse structure of some gingerbreads and chocolate cakes. Fortenbacker and Koch made a study of the effect on gluten of various concentrations of acids, alkalies, and salts found in baking mixtures. They found the gluten to be more soluble in alkaline solutions, for concen- trations used in baking mixtures, than in acid solutions. In fact, the gluten disintegrated rapidly in alkaline solutions of increasing concentration, so that the gluten discs could be left in only for short periods or they could not be lifted to be weighed. Because of the gluten being dispersed it loses some of its elasticity. The cakes are tender owing to the dissolving of the gluten. The gingerbread batter like all cake batters contains enough buffer sub- stances so that with the addition of alkali it does not become as alkaline GINGERBREAD 517 as it otherwise would. Thus with the addition of 2 teaspoons of soda, Experiment 87,1, the batter is not as distinctly alkaline as would be expected, though the flavor is quite evident. With the large proportion of soda a hollow may form in the center of the gingerbread during baking. This is more likely to develop if the batter is allowed to stand a short time before baking. The soda causes partial dispersion of the gluten. The baking sets the crust, but the interior of the cake being baked last, the soda continues its action on the gluten during part of the baking with the result that the cake may be level across the top but have a hollow in the center. Sometimes the cake sinks across the top instead of forming the hollow in the center. With longer mixing and greater attenuation of the gluten the sinking does not occur.