Leavening agents are substances that are commonly used in baking to make food rise and voluminous. Various alternatives are accessible to leavening agents that can be used interchangeably based on the recipe you are preparing or the flavor you want to achieve. Some equivalent words to leavening agent include baking powder, yeast, baking soda, cream of tartar, and sourdough starter. The baking powder is made of sodium bicarbonate and an acidic substance like cream of tartar, while yeast is a single-celled fungus that can come in various forms, like dry rapid-rise, or wet cake yeast. Baking soda is an alkaline substance that reacts with acidic ingredients, while cream of tartar is similar to baking powder but solely an acidic substance. Lastly, a sourdough starter is made of fermented flour and water.