Yeast and baking powder are both used to make dough rise. Both provide the carbon dioxide gas that stays as bubbles in the dough. Yeast is a living micro-organism. It produces carbon dioxide gas from the sugars that are present in the dough. Apart from carbon dioxide gas several other aromatic substances and flavour compounds are formed.

Baking powder consists of a number of substances, but commonly it is a combination of a carbonate and a dry acid. When a carbonate comes into contact with water and acid, it will dissociate into several components. In this process carbon dioxide gas is released, but without the release of aroma substances or flavour compounds. The taste of the product will therefore not be affected.