Yeast Balloon Experiment

On Thursday afternoon the Eagles conducted an experiment with yeast and balloons as we have been looking at living organisms. They had a film canister containing a teaspoon of sugar, a packet of yeast and 10ml of warm water. They placed a balloon over the top of the canister then measured its diameter every 10 minutes. Some of the balloons (especially the ones by the climbing wall) became huge - the biggest measured 28cm. We kept one in the fridge too - we thought light might affect the size but it still grew to 12cm even though it was dark. So we worked out that the yeast needed warmth and food to release carbon dioxide. Some of the balloons didn't really inflate and we discovered, when we looked at them, the rubber had stretched very thinly and allowed the gas to escape.

science balloons