Baking Powder

Let's talk about baking powder, and let's talk honestly, because half of what home cooks believe about it is nonsense.

Baking powder is not one substance. It is soda plus acid plus a bit of starch to keep them apart in the tin. Add water, and the two meet, and they fight, and that fight makes gas. The gas makes bubbles. The bubbles make your dough rise. That's the whole mechanism, no mystery in it.

Choose it by look and by behaviour, not by the label alone. Fresh powder is a fine, dry powder, pale and loose, running like sand through your fingers. Old powder clumps, forms little lumps you have to crush with a spoon. Drop a spoonful into warm water — if it doesn't hiss and foam at once, throw it out. It's dead, and dead powder gives you a flat, heavy cake.

Some people say more baking powder means more rise. No! Too much, and the bubbles grow too large and burst before the structure sets — your crumb collapses, and the taste turns soapy and bitter. That's the mistake: cooks doubling the spoon "to be safe," and ending up with a cake that fell in the middle and tastes of chemistry, not of butter and eggs.