Last week I made the buttermilk biscuits from the current DCCC pick, Dairy Hollow House Soup & Bread: A Country Inn Cookbook by Crescent Dragonwagon. This recipe was an opportunity to use some King Arthur cake flour I’d been meaning to try (Crescent Dragonwagon recommends using cake or pastry flour, such as While Lily, for ultra tender biscuits), some of my homemade lard, and something else lingering in my fridge: baking powder that had long outlived its expiration date.

Before just chucking it out, I decided to test it using one of the many baking powder tests found online. The tests are all the same: you pour hot water over some baking powder, and if it fizzes and bubbles, it’s good to use. A typical ratio is 1 teaspoon baking powder to ⅓ cup hot water.

My nearly three-year-old baking powder fizzed and bubbled, so I used it. (This was courting disaster because I knew the standard advice is to replace baking powder one year after it’s been opened, and some even recommend replacing it six months after it’s been opened.)

The result was biscuits that rose, but just slightly, had a substandard crumb, and, worst of all, had a detectable chemical aftertaste.

Buiscuts made wiith old baking powder

Buiscuits made with fresh baking powder

I made the biscuits again with fresh baking powder, using the same brand (Davis Double-acting Baking Powder.) The second batch rose a bit more, had a much more tender and finer crumb, and there was no chemical aftertaste.

The Conclusion: Replace your baking powder regularly, and don’t rely on the baking powder test, unless you’re schooled in detecting just how much bubbling is enough bubbling. The video shows old and new baking powder being tested, and shows that there is a slight difference in the amount of bubbling. (If you want to train yourself to become the next human bubble-o-meter, this video will be a help.)