What is baking powder?
Many recipes ask for baking powder, but what actually is it?
Baking powder is a levering agent that is often added to cakes to ensure a fluffy and light sponge. It is a dry chemical levering agent made up of a carbonate/ bicarbonate (base) and a weak acid. The base and acid are prevented from reacting too early by the presence of a buffer such as corn starch. Most baking powders are made up of bicarbonate of soda (base) and at least one or more salts (acid).
Baking powder is added to batters such as sponges to give high volumes and a light, fluffy texture. It works by releasing carbon dioxide gas into the batter through the acid-base reaction causing bubbles to expand in the wet mixture, causing it to rise. An acid-base reaction is when combined with water the bicarbonate of soda and acid salts react the produce carbon dioxide gas. This creation can be chemically shown as: NaHCO3 + H+ → Na+ + CO2 + H2O
Baking powder has the same effect as yeast and is used when fermentation isn’t desirable or where the batter doesn’t have the elastic structure needed to hold the gas bubbles for more than a few minutes. Carbon dioxide is released faster during a acid-base reaction than through fermentation meaning that using baking powder is a faster process that fermentation.