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Experimentbeginnerdraft

Baking powder: cold versus hot

Also searched as: baking powder experiment, testing raising agents

In short: Baking powder fizzes twice: once when it gets wet, and again in the heat.

Picture it

Like an alarm clock with a snooze button: it rings briefly when mixed, and then properly in the hot oven.

Before · Afterbaking powder in
cold water
hot water
Schematic
You need · 5 minutes
  • baking powder
  • two glasses
  • cold water
  • hot water

Hot water: adults do the pouring.

How it’s done

Sequence · Step 1 of 3
123

Put a teaspoon of baking powder in each glass.

All steps as a list
  1. Put a teaspoon of baking powder in each glass.
  2. Pour cold water into the first and hot water into the second.
  3. Watch where it fizzes more.

What you see

In the cold glass it fizzes a little; in the hot one, much more.

Why it happens

contains two acids: one reacts with water straight away, the other only with heat. That way the cake rises properly exactly when it is in the oven.

Related entries
Chemical leavening
Sources · 1
  • Harold McGee: On Food and Cooking (2004)