Bi-Carb Soda

Baking soda, bicarbonate of soda, or just bicarb is an alkali which is used to raise soda breads and full-flavoured cakes. It needs an acid (as well as moisture) to activate it so is often combined with cream of tartar, yoghurt, lemon juice, apple cider vinegar, buttermilk or milk. Bicarbonate of soda works by giving off carbon dioxide which expands the mixture. Once the mixture is cooked, the carbon dioxide is replaced by air leaving a light cake or bread.