Don't Ruin Your Next Batch Of Cookies — Test This Ingredient Like Julia Child First

One of the most frustrating scenarios for home bakers is to prepare a recipe meticulously only to have the final baked product literally fall flat. This can happen with cookies, muffins, brownies, breads, and more. While a number of things could have gone wrong, the culprit might be your baking powder. Baking powder is a rising agent; it produces carbon dioxide bubbles which lift your mixture, making the final baked good look great and feel fluffy. When baking powder dies, your cookies and other treats simply won't rise. Sometimes this can happen even if your baking powder hasn't expired, making it difficult to know for sure if your baking is going to be successful. Fortunately, there's an easy step you can take which Julia Child recommends that will help you determine if that vital ingredient is fit for use: Just add water.

Place 1 teaspoon of baking powder in a small bowl and pour ½ cup of boiling water over it. If the mixture bubbles up immediately, the powder is alive, active, and good for baking. If the water stays calm, it's time to replace the ingredient. While most people would use a kettle or pot to heat water on the stove for a task like this, Child sometimes brought her water to a boil using a very unique method. She would plunge a hot iron rod (not electric) into a pot of water to bring it up to temperature very quickly.

Generally, baking powder will stay good and active for anywhere from six months to a year, but heat, humidity, and moisture will affect its shelf life. So, even if the expiration date on your can of powder has passed and you've stored it in good conditions, it's worth testing with hot water, as it might still be good to use. At the same time, your three-month old can might be useless if you live in a humid environment. For maximum longevity, store baking powder in an airtight container in a cool, dark place.

If you discover your baking powder-hot water mixture doesn't bubble and you have everything else you need to create your family's legendary chocolate chip cookie recipe (upgrade it by using Nutella chips), you don't necessarily need to drop everything and run to the store for a new package. You probably already have the things you need for a good baking powder substitute in your pantry. And, no, it's not as simple as just using baking soda, which is not interchangeable with baking powder on its own. That being said, it is part of the substitute. For every teaspoon of baking powder your recipe calls for, mix together ¼ teaspoon baking soda, ½ teaspoon cream of tartar, and ¼ teaspoon cornstarch. In a pinch, egg whites can also act as a baking powder substitute.