What is it?

Baking powder is a chemical leavener. White and soluble, it produces carbon-dioxide gas when mixed with a liquid; the resulting bubbles cause pancakes, waffles, breads, and cakes to rise. Unlike baking soda, which needs an acidic ingredient added to it in order for it to react, baking powder contains both baking soda and an acid, which means it can be mixed with any type of liquid and create its own bubble-producing reaction.

Double-acting baking powder is the most common baking powder on the market. It contains two types of acid (usually cream of tartar and sodium aluminum sulfate), one that reacts when the batter is first moistened, and one that reacts later in the heat of the oven.

Sodium aluminum sulfate can create a bitter metallic aftertaste, especially when used in high amounts. The downside of using aluminum-free baking powder is that you need to get your baked goods into the oven quickly, since most of the leavening power is unleashed once the wet ingredients are added. Its shelf life can also be shorter, as it’s more vulnerable to ambient moisture if not sealed properly.

Whether you’re using aluminum-free baking powder or not, its a good idea to test your baking powder for freshness if it’s been stored for a while. To do this, check for caking or lumping, an indication that the powder has absorbed moisture and is past its prime. If no lumping is apparent, mix a teaspoon of the baking powder with hot water; if it bubbles vigorously, then the powder is still active.

Don’t have it?

Per 1 tsp. baking powder, substitute 1/4 tsp. baking soda plus 5/8 tsp. cream of tartar

How to store:

Baking powder will keep for quite a while kept in a cool, dry place. But its leavening powers will less over time, so if it’s been a while, check the expiration date, you may need to open a new can. To test for freshness, combine 1 tsp. baking powder with 1/3 cup hot water; it it bubbles enthusaistically, it’s still got oomph.

Cross Reference

baking soda

Recipes

• 
  Recipe

  Coffee Crème Bundt Cake

  This glorious coffee-flavored Bundt, excerpted from The Joys of Baking, is more sweet than coffee and has a gooey, condensed milk glaze that you may have to resist eating with…

• 
  Recipe

  Orange, Olive Oil, and Rosemary Cake

  浸渍的橙色部分和一块的糖浆of crème fraîche embellish this rustic cake, a nod to the Sephardic desserts of Italy and Spain. Olive oil gives the…

• 
  Recipe

  Italian Neapolitan Cookies

  These buttery cookies are a traditional Italian treat and easier to make than they look. The recipe uses one dough divided onto three portions and flavored with almond, mocha, and…

• 
  Recipe

  Chocolate-Dipped Cherry-Pistachio Biscotti

  These sweet and tart cookies are crunchy because they’re baked twice, which makes them ideal for dunking into espresso or dessert wine. Dipping them in melted chocolate is optional, but…

• 
  Recipe

  Spiced Cider Doughnuts

  In the fall, almost every pick-your-own orchard in New England serves its family’s version of cider doughnuts. They’re all wonderful, but I’ve been told many times that mine—warmly spiced and…

• 
  Recipe

  Cheddar-Zucchini Pancakes with Poached Eggs

  Vegetable pancakes are versatile. You can serve them with a poached egg (as shown here) or with a salad (or both) for a light but satisfying lunch or dinner. Or…

• 
  Recipe

  Strawberry-Rhubarb Blitz Torte

  Possibly called “blitz” because the stunning cake can be baked, cooled, and assembled quickly compared to traditional layer cakes, this dessert is a showstopper. Tender, golden cake layers are topped…

• 
  Recipe

  Mint Chocolate Bars

  A minty buttercream gets sandwiched between two layers of chocolate goodness: a chewy brownie and a rich ganache. The crème de menthe gives the buttercream the perfect hint of holiday…

• 
  Recipe

  Coffee Blondies

  These chewy cookies have all the classic features that you love in a blondie—toasted nuts and chocolate chips—plus a caffeinated boost from coffee. To make sure the flavor shines through,…

• 
  Recipe

  Pumpkin Bars with Brown Butter Frosting

  These cakelike bar cookies use elements that are both traditional and fancy: a simple pumpkin cake base topped with a nutty brown-butter frosting.