Bicarbonate of soda, is an alkali which is used to raise soda breads and full-flavoured cakes such as gingerbread, fruit cake, chocolate cake and carrot cake. It needs an acid (as well as moisture) to activate it so is often combined with cream of tartar, yogurt, buttermilk or milk. Bicarbonate of soda can also be used as a cleaning product as it is a super-effective but gentle abrasive and a great natural deodoriser.