Madison's science fair experiment

Madison put 1 tsp. active dry yeast, 1 tbs. white sugar, and 1/4 c. warm water in 16 clean, numbered 20 oz. bottles.  In 4 bottles, she put only sugar and water for control bottles.  I put the balloons on, and Madison swirled the contents.  She randomly picked 4 bottles with yeast to go into each of the 4 temperature treatments, along with one control bottle without yeast.  Every 30 minutes for 6 measurements, she recorded the circumference of the balloons and the temperature of each treatment.  Treatment 1 was in the fridge (~38F).  Treatment 2 was room temperature, sitting on the counter (~72F).  Treatment 3 was a water bath sitting on a heating pad set on medium (~84F).  Treatment 4 was a water bath sitting on the stove set on high (~110F).  Madison's hypothesis that different temperatures would affect the amount of carbon dioxide made by the yeast appears to be supported by the data she gathered, although we haven't analyzed (e.g. graphed) the data yet.  We've had a great time working on it so far.  We still have quite a bit to do before the big day on Jan. 29, but it's great to have the experiment out of the way!

Originally posted on www.myspace.com/wannabedutch on 01/17/07.