What really is baking powder, this white powdered substance we reach for each time we bake a cake, fry a fritter or make something that needs a lift? It hasn’t always been as refined as the form we find in the market these days.

Baking powder is a leavening agent that is a combination of baking soda, cream of tartar and a moisture absorber (like cornstarch). It has the action of yeast but it acts much more quickly. It is used in batters where there is no acid present, such as baked goods like cookies, cakes pastries, quick breads, pies, etc.

It makes these types of foods voluminous by allowing gas formation when an acid comes into contact with it and/or when it’s heated. Baking powder acts immediately upon addition of water; therefore, the filler cornstarch is added to absorb the moisture and prevent premature activity.

Today, most baking powders are double acting, which means they react twice; the powder contains one acid that dissolves when it comes into contact w...