Salt rising bread is fundamentally different from other breads because yeast does not play any part in the fermentation process. Instead, this specialty bread is leavened by a unique bacterial ferment. The bacterium which causes this fermentation is called Clostridium perfringens. Since no yeast cells are present, the dough is aerated entirely by the gases produced by the bacteria. The strong proteolytic action of this special ferment develops the exceptionally close grain and fine texture typical of salt rising bread. The acid by-products of the fermentation account for the distinctive cheese-like flavor and aroma, as well as the extra-white color of the crumb.
The fermentation loss in salt rising bread is less than one half of one percent. There are several reasons for the extremely small fermentation loss in salt rising bread. First, salt rising fermentation does not produce any alcohol or other highly volatile substances which evaporate. Secondly, salt rising fermentation produces mostly hydrogen gas, which is 22 times lighter than carbon dioxide. Very little gas is wasted in salt rising bread. Thus, the salt rising sponge should be taken when it first begins to drop. The bacterial ferment will work itself out if the sponge is over-aged, and the bread will not rise properly in the pans. Salt rising bread dough should be made into loaves and put into pans immediately after mixing.
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