I have been working on a cookie story for the Holiday Best special issue Canadian Living puts out for Christmas on international cookies. Quite often in Scandanavian countries ammonium bicarbonate is used as a leavening agent in cookies. I was curious to know why this would be the leavening of choice instead of baking soda or powder. I found out a few interesting facts: 1 - Ammonium bicarbonate was used in things like cookies because it did not impart a bitter taste the way some early version of baking soda and powder did. 2 - The ammonia gas gets trapped in baked goods like a cake where it cannot escape and will make the cake smell bad, so it is only used in cookies that are flat and porous where the surface area allows to ammonia to disappear. 3 - If you don't store it in an airtight jar it will evaporate. 4 - Baking powders were invented in Germany during a famine when food was scarce and people were dying. Using baking powder instead of yeast preserved the flour in the baking process instead of it being eaten by the yeast. 5- Ammonium bicarbonate is also called Hartshorn, or Horn Salts. 6 - Hartshorn literally means ground deer horn which was supposedly used before ammonium bicarbonate went into commercial production - not clear if it has the same properties though, so don't bother trying to grind up antlers. 7 - Harsthorn, Horn Salts or ammonium bicarbonate were used as smelling salts. Click here to sign up for Christine's Food for Friends e-newsletter!