Leavening is a set of chemical and physical reactions which, by means of natural or chemical components (sourdough starter, brewer's yeast, Baker's yeast, sodium hydrogen carbonate, ammonium hydrogen carbonate, sodium acid pyrophosphate, monocalcium phosphate, magnesium hydroxide carbonate, etc.) generate:

• gas CO₂
• gas NH₃
• porosity
• bubbles

Most leavening agents also have the function of softening, lightening and posing the dough and the final product, and each has its own characteristics that make it suitable for different final products: sodium bicarbonate raises the pH, sodium pyrophosphate must be added with caution as too much leads to a sour taste, monocalcium phosphate produces a faster leavening and is widely used in the USA, magnesium carbonate hydroxide protects against moisture, ammonium bicarbonate increases volume.

Ammonium carbonate and sodium carbonate generate the leavening chemical gases CO2 and NH3 by a dissociation process and create, in addition to water vapour, gaseous bubbles in the dough during baking If sodium chloride is added, a strong ionic force is achieved. In the presence of citric acid, tartaric acid or lactic acid, which are weak organic acids, the release is slower. 

Sourdough is the most widely used natural yeast and is a complex microbial ecosystem containing milk enzymes and yeasts that can be used in water and grain doughs and is also used to improve the quality of gluten-free bread.

Leavening agents can be in the form of dry yeast or baking powder.

The optimum water temperature is around 20°C-30°C. The higher the water temperature, the greater the density of the mixture. Another important factor is the hardness of the water: the harder it is, the more residue there will be on the plate. Purified water makes the final product taste better.

Against wheat gluten proteins, lactic acid bacteria such as Weissella paramesenteroides, Lactobacillus sakei and others are used to provide baked goods suitable for coeliacs, based on their proteolytic activity.

For more information:

Raising agents studies