The reaction of baking soda with other ingredients provides leavening for some baked goods. Only small amounts are needed. Most recipes recommend that you combine the baking soda (and baking powder or salt when used) in with the other dry ingredients (such as flour or sugar) before mixing in with other ingredients. This way the baking soda is more evenly distributed. If you mix it with liquids first, it may clump. You can use baking soda and cream of tartar to substitute for baking powder.[1] Other leavening agents include salt, baking powder or yeast.