As a follow-up to our investigation into the best environment for yeast to respire, we made bread rolls on Monday. We had learnt that when yeast respires it produces carbon dioxide as a waste product - as all living things do. Bakers, however, take advantage of this fungi's waste gas and use it to rise their dough.

Form 6 mixed together 250g strong bread flour, half a teaspoon of salt, 7g of our microbes and about 150ml of water. They then kneaded the dough, stretching it to develop the gluten proteins in the flour. Once they had a smooth and elastic dough, they divided it into three and each pupil shaped their roll to their design. The dough was left to prove in the sunshine.

The term prove comes from the fact that we are proving that the yeast is alive, busily 'eating' the flour, using that to respire and produce carbon dioxide making the dough lovely and light. The rolls were then popped into a hot, steamy oven for about 20 minutes. I think that the children devoured them in about 2 minutes! Do try this at home. Remember, without this fungi, doughnuts would not exist!