Baking soda; Sodium bicarbonate

Baking soda, or sodium bicarbonate, produces carbon dioxide gas to inflate batters in the same way as baking powder (baking soda is an ingredient of baking powder). Baking soda starts to release gas as soon as it comes into contact with moisture, so products in which it is used should be baked as soon as possible after mixing. (This is especially true if baking soda is used alone and not used in combination with baking powder.) Recipes that use baking soda for leavening must contain an acid ingredient because without an acid, baking soda will produce a pungent and unpleasant flavor when the product is baked. Baking soda alone (without an acid) becomes carbon dioxide gas and sodium carbonate when it is heated. The carbon dioxide gas is desirable for producing air bubbles and the leavening effect, but the sodium carbonate has a disagreeable soapy taste and is moderately alkaline. When an acid is introduced (buttermilk, chocolate, citrus juice, sour cream, brown sugar, honey, or molasses, to name some of the ingredients commonly utilized), the gas is produced more rapidly, which leaves behind a milder form of the sodium. In addition to its leavening properties, baking soda also helps darken the baked product to some degree, which can add to a more appetizing appearance. Store sodium bicarbonate in an airtight container.