Brown Soda Bread and Scones

Bicarbonate of soda (or bread soda) is the raising agent used in all soda breads. It is an alkali, and even though it is one of the ingredients used in baking powder, it can be used on its own to react with an acid, e.g. sour milk or buttermilk. This produces bubbles of carbonic acid which fill up with air and rise the bread. So the main thing to remember is: use bicarbonate of soda (bread soda) with buttermilk or sour milk, and baking powder—which is a mixture of acid and alkali substances