Baker’s Ammonia—also known as ammonium carbonate or hartshorn—is a traditional leavening agent used in many old-fashioned recipes, especially for crisp cookies and crackers.

Unlike baking powder or baking soda, Baker’s Ammonia produces an exceptionally light, crisp texture without leaving behind an alkaline aftertaste. However, it’s not suitable for cakes or other dense baked goods. The ammonia gas released during baking must be able to fully escape—otherwise, it can become trapped, resulting in an unpleasant odor or taste.

You may notice a strong ammonia smell during baking, but this is completely normal and temporary. When heated, ammonium carbonate breaks down into three gases: ammonia, carbon dioxide, and water vapor. These gases provide leavening and contribute to crispness, and they completely dissipate during baking. Any trace odor will vanish once the baked goods have fully cooled.

Storage Tip: Baker’s Ammonia evaporates when exposed to air, so store it in a tightly sealed container. It doesn’t spoil, but if left unsealed, it can gradually lose its potency and simply disappear.

You can purchase Baker’s Ammonia on our website.