Test Kitchen tips: Testing baking soda and powder for freshness

Jacqueline Kennedy's waffles.
(Robert Lachman / Los Angeles Times)

Baking soda and baking powder are only as good as their freshness when it comes to baking in the kitchen. Used to leaven everything from cakes and biscuits to doughnuts and waffles (like Jackie Kennedy’s waffle recipe, which can be found below), they’re the ingredients that help a dough rise as it bakes. And like any ingredient, they can lose their effectiveness as they age, and there’s nothing worse than having a cake fail because the ingredients weren’t any good.

Because they do lose effectiveness with time, it’s best to buy both baking soda and powder in small quantities. Store both in sealed containers in a cool, dry place, and label when you’ve opened them (baking powder can start to lose its effectiveness within a few months of opening).

There are simple ways to test both baking soda and powder for freshness:

  • To test baking soda, place a few tablespoons of vinegar in a small dish or measuring cup, then stir in about a teaspoon of soda. The mixture will immediately begin to fizz if the soda is still active; if there’s little to no reaction, it’s time to buy a new container. (You can still keep the old one in the fridge to help neutralize odors).
  • To test baking powder, place a few tablespoons of hot water in a small dish or measuring cup, then stir in about a teaspoon of powder. Like baking soda, the mixture will begin to bubble and fizz if the powder is still active; if there’s little to no reaction, it’s time to get some more.

If you have any kitchen tips or questions you’d like me to explore, leave a comment below or shoot me an email at



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Jacqueline Kennedy’s waffles

Total time: 30 minutes

Servings: 4

Note: Adapted from “Many Happy Returns: The Democrat’s Cook Book, or How to Cook a G.O.P. Goose,” compiled and edited by Ethel Longstreet & Olga Marcus.

1/2 cup butter (1 stick)

1 tablespoon sugar

2 eggs, separated

1 cup plus 1 tablespoon sifted cake flour

1 cup buttermilk

1 pinch salt

4 teaspoons baking powder

1. Using an electric mixer, cream together the butter and sugar. Add the egg yolks, one at a time, until incorporated. Add the flour and buttermilk, a little at a time, alternating until each is incorporated. Stir in the salt and set aside.

2. In a separate bowl, whisk the egg whites to stiff peaks. Gently fold the whites into the batter, then gently fold in the baking powder until incorporated. The mixture will be thick and fluffy.

3. Bake according to the manufacturer’s instructions for your waffle maker. Serve immediately.

Each serving: 408 calories; 8 grams protein; 36 grams carbohydrates; 1 gram fiber; 26 grams fat; 16 grams saturated fat; 168 mg. cholesterol; 626 mg. sodium.