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 — with ordinary milk.
Mix the dry ingredients well together. Rub in the butter. Make a well in the centre and add the beaten egg, then immediately add most of the sour milk or buttermilk. Working from the centre, mix with your hand and add more milk if necessary. The dough should be soft but not sticky. Turn out onto a floured board and knead lightly, just enough to shape into a round. Flatten slightly to about
© 1989 Darina Allen. All rights reserved.