BAKING SODA VS. BAKING POWDER
Baking Powder and Baking Soda are both chemical leaveners used to make batters rise. Quick breads, cookies, cakes, and biscuits all get their lift from these two basic baking ingredients.
Baking soda needs an acidic ingredient to react with to release carbon dioxide, the gas that is released in small bubbles to give the baked goods their lift. Acidic ingredients in baking are yogurt, sour cream, buttermilk, molasses, honey, citrus juice, and even vinegar. (This is why you often find white vinegar as an ingredient in red velvet cake). Use baking soda as specified in your recipe. Too much will produce flat baked goods and leave a metallic taste in your cakes or cookies. Baking soda is also known to create browning in baked goods.