However, if the mixture is acidic, baking powder's additional acids will remain unconsumed in the chemical reaction and often lend an unpleasant chemical taste to food.
I've tasted that! A while ago, I made my yogurt biscuits (where yogurt is acidic), and I trusted the Bakewell comment to use like baking powder ... yowzah! It tasted awful! But now I have a full explanation, so I know how to avoid that taste in the future. Whew!
My current biscuit recipe is this Buttermilk Biscuit recipe, made with my usual substitutions (whole wheat flour, homemade baking powder, coconut oil, and soured rice milk). Yummy!