baking powder

A powder used in baking as a substitute for yeast. It consists of tartaric acid, bicarbonate of soda, and rice or potato flour. These ingredients must be powdered and dried separately, and then thoroughly mixed together. The flour is added to keep the powder dry, and prevent it absorbing moisture from the atmosphere. As the combination of tartaric acid with bicarbonate of soda produces tartrate of soda, which is an aperient, it would be better if manufacturers of baking powders would substitute sesquicarbonate of ammonia for the bicarbonate of soda. Baking powders are generally free from adulteration, although alum has sometimes been found, but in very minute quantity.