The science of bread22 Nov 2018
While investigating the activity of yeast, guess what Form 6 made?
We knew it had to happen at some stage, but we always hope it won't. It rained! So now what do we do?
In reality, wet break is not so bad, as there are plenty of creative things we find to occupy ourselves with. One day this week, we brought out the interlocking cubes and let our creativity flow. The result - an imaginative picture frame and an ambitious bridge between the desks!
In Science, we have been learning about Microbes and had a lesson on hand washing. First we looked at our hands under UV light to see the unseen bacteria on them. Then we watched a short video on how pathogens can be spread from our hands onto everything we touch, making other people ill. We learnt how to wash our hands properly, singing Happy Birthday to ourselves twice. Under the UV lights our hands looked MUCH cleaner, some were even spotless!
We then carried out a sophisticated experiment to investigate the conditions that yeast likes best to work in. It required accurate measurements and a steady hand. We put yeast and sugar solution into boiling tubes and carefully put a balloon over the neck of the tube. We put half the boiling tubes in ice cold water and the other half in warm water at about 40 degC. We came back after lunch to find that the balloons in the warm water had inflated a little and were standing upright. This showed that yeast likes sugar for its food and being in warm conditions because that is when it produced the most carbon dioxide gas which filled the balloons.
Then on Thursday, Form 6 used yeast to make bread. We put into practice our best hand washing techniques before we started. We checked we had completed the 5 steps preparing to bake. The yeast we had put in digested the flour and respired, producing the gas carbon dioxide. It's the gas that makes the dough rise.