Skill 11: Raising Agents (AQA GCSE Food Preparation & Nutrition): Revision Note

Egg

Whisking eggs traps pockets of air within the liquid batter; this is known as a gas-in-liquid foam

Whisking egg whites to make a meringue, and whisking whole eggs in cake batter to make a sponge

Chemical

Self-raising flour, baking powder and bicarbonate of soda are examples of chemical raising agents; they produce carbon dioxide bubbles when heated which helps doughs and batters to rise

Using self-raising flour to make a cake batter

Steam

Water present within a mixture evaporates when heated, producing steam which raises the dough

Choux pastry uses steam to rise the pastry dough

Biological

Yeast is added to bread doughs which ferments to produce gas; the gas expands during proving and baking, raising the dough

Bread rolls, focaccia, naan bread