Investigating Alcoholic Fermentation and the Affects of Yeast on Dough

964 Words Apr 29th, 2002 4 Pages
Biology Lab Report

Investigating Alcoholic Fermentation and the Affects of Yeast on Dough

Aim: The aim was simply to investigate whether or not yeast had any affect on causing dough to rise when baked and to experiment with alcoholic fermentation eg. to see if it gave off carbon dioxide.

Introduction: Following a few weeks of fermentation theory, groups of three to four were assigned and told to conduct a series of experiments involving the affects of fermentation. My group consisted of myself, Won Jin, Brendan and Sun-Ho and we chose to investigate alcoholic fermentation and the affects of yeast on dough, more specifically to see if yeast caused the dough to rise in anyway. We followed the instructions in our biology textbook on
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We placed both mounds of dough on top of a windowsill where we would leave it for an hour. We though this was a suitable place as the sun had already caused the surface to warm up. After an hour, the Dough mound with yeast did rise while the Dough mound without, didn't. Not much of a surprise. I'll return to the rest of our results in my conclusion.

For our second experiment (Alcoholic Fermentation) we moved to the Chemistry lab, from the kitchen, in order to better our chances of conducting a good experiment in a suitable environment. Our teacher, Mr. Barling, provided the Liquid Paraffin used in this experiment.

We poured the 10 per cent Glucose solution into a test tube and boiled it to be rid of any excess oxygen that could contaminate the experiment by affecting the yeast. After cooling the test tube, we added a little Yeast and poured a thin layer of Liquid Paraffin to, once again, stop oxygen from reaching the yeast. The layer of Liquid Paraffin created a surface on top of the Glucose/Yeast solution disabling any foreign gasses to mix with it. To better conduct the experiment, we set up an additional test tube and followed the instructions exactly, except this time we didn't add any Yeast to the Glucose in order to see if Yeast really did cause the

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