Sponge and Dough - Purpose

Purpose

The sponge method is used for 3 different reasons: taste, texture and chemistry.

The flavour that is created is dependent on the ingredients used and the fermenting yeast. Just like sourdough, the longer the ferment, the greater the taste difference.

Sponge doughs were used before bread improvers were invented. Texture is partly a byproduct of the chemistry going on in the fermentation, which does several important things such as activate the different enzymes (protease and amylase) needed to leaven bread. Modern grain-harvesting practices have reduced the naturally-occurring enzymes that grains had in former times, a result of no-longer-used grain-storage processes, so today small amounts of enzymes are routinely added to flour by manufacturers, often in the form of malted barley or sprouted grain.

Proteases, dependent on their time of action and concentration levels, soften the gluten in the dough, hydrolyzing peptide bonds, increasing dough extensibility which allows the protein matrix to stretch out as the mix expands, thus leading to increased baked volumes and better structure.