Ammonium bicarbonate is a white crystalline powder used in flat, spiced cookies, such as gingerbreads, and in eclair paste. It must be dissolved in the cold liquid portion of the batter. At room temperature, decomposition of $$\ce{CO2}$$ in the batter is minimal. When heated to approximately 60°C (140°F) decomposition is more noticeable, and at oven temperature, decomposition takes place in a very short time. Ammonium bicarbonate should only be used in low moisture-containing products that are not dense. Providing that these conditions are met, there will be no taste and odor remaining from the ammonium.