Book 9, Question 68
Why Does Yeast Need Warm Water, Not Hot?
Yeast needs warm water, not hot, because yeast is a tiny living thing! Warm water wakes it up, but very hot water can kill it. Dead yeast cannot make bread rise.
More fun facts
- Yeast is a living thing, and like other living things it needs food and water.
- When yeast gets warm water and some sugar to eat, it becomes active.
- Very hot water kills yeast and stops dough from rising.
- If yeast gets as hot as 60°C, it dies and stops working.
- In a classic experiment, a balloon on a bottle of yeast, sugar and warm water starts to puff up after 15 or 20 minutes in a warm place.
Sources: Scientific American, BBC, BBC
Questions kids ask
What blows up the balloon?
Active yeast gives off carbon dioxide gas, which fills the balloon.