So what difference does baking powder really make?
To find out, I made five batches of biscuits that were identical except for the amount of baking powder used. Each batch uses two cups of flour and normally makes 8 biscuits, but I only cooked three biscuits from each batch so that I could make sure the baking conditions were exactly the same for all of the biscuits.
- Batch 1: 1/2 teaspoon baking powder
- Batch 2: 1 teaspoon baking powder
- Batch 3: 2 teaspoons baking powder
- Batch 4: 4 teaspoons (1 tablespoon) baking powder
- Batch 5: 8 teaspoons (2 tablespoons) baking powder
Both taste testers (my wife and I) thought that batches 1 and 2 (with only a tiny amount of baking powder) were noticeably denser and moister than the others. The texture wasn't the nice, flaky, classic biscuit texture we both like.
For batches 3, 4 and 5 (with half to double the base recommended baking powder amount), the taste difference was almost indistinguishable. My wife thought the batch with the most baking powder was best, while I thought it tasted a tad too salty and chemically. My favorite was the middle batch, with two teaspoons of baking powder, but my wife thought this one was a little too dense.
More baking powder makes the biscuit rise more (imagine that!). About 1 tablespoon of baking powder per 2 cups of flour seems to be about the right amount, but even halving or doubling this amount should not ruin your biscuits.