I recently came across a cookie recipe that called for "baking ammonia". What is that?--Peggy
Baking ammonia, or ammonium bicarbonate, was used before the advent of baking soda and baking powder. It is a chemical leavening agent originally made from the horns of deer. The chemical formula is NH4HCO3. When heated, baking ammonia breaks down into ammonia (NH3), water and carbon dioxide. The carbon dioxide makes cakes and cookies rise, the same way that carbon dioxide given off by other chemical leaveners does.
Because the word 'hart' is an old term for deer, baking ammonia is also known as hartshorn.
Because baking ammonia gives off ammonia gas, it can affect the flavor of the finished product. For that reason, it is best used for thin products, such as cookies, where the ammonia gas can escape easily, and drier products. Moist products such as cakes will hold more of the ammonia gas.
Baking ammonia can be purchased at some drug and specialty food stores. It usually comes as a lump and needs to be ground to a powder before use. It should be kept in a well sealed container.
Do not confuse baking ammonia with regular, household ammonia used as a cleaner, which is poisonous.