Similarities and Differences

• Baking soda and baking powder are chemical leaveners that cause carbon dioxide bubbles to form and expand when combined with moisture and heat. The two both contain sodium bicarbonate, a highly alkaline substance made primarily from trona ore, mined in Wyoming. Baking soda contains nothing but sodium bicarbonate, and must be combined with an acidic ingredient to neutralize its acidity and create a chemical reaction. Baking powder contains sodium bicarbonate, as well as cornstarch to absorb moisture, and an acidic ingredient, such as cream of tartar. It needs no additional acidic ingredients to neutralize it.

The Ingredient List

• Baking soda will alter the taste of muffins if you don't make a few changes to the ingredient list. Be sure to use an acidic ingredient in the batter, such as buttermilk, brown sugar, molasses, fruit juice or fruit puree. Otherwise, the baking soda won't be neutralized, giving the muffins a soapy, bitter flavor. Whisk the baking soda into the dry ingredients before you add it to any wet ingredients so it dissolves completely. Small, unincorporated bits of baking soda also give muffins a bitter taste, and can hamper the muffins' ability to rise.

The Ratios

• Because baking soda contains only sodium bicarbonate, it's much more potent than baking powder. In general, use only 1/4 teaspoon baking soda for every cup of flour in the muffin recipe. If you use more, the acid in the batter won't completely neutralize the baking soda, and you'll end up with bitter-tasting muffins.

Tips for Success

• In addition to changes in taste, muffins made with baking soda instead of baking powder may have a slightly coarser texture. To counteract this tendency, use pastry flour or cake flour instead of all-purpose flour, and stir the muffin batter carefully so you don't toughen it further. Most commercial baking powder is double-acting, meaning that it has two acids -- one activated by moisture and the other activated by heat. This means that you can wait a few minutes before putting the muffins in the oven. Even if the first round of bubbles have dissipated, the second round will still cause the muffins to rise. Baking soda is not double-acting, so be sure the oven is preheated and bake the muffins immediately.