Yeast Beasts in Action Lab Investigation

In this lab investigation, my table group had the ability to test Dr. Pepper, skim milk, and Milk of Magnesia to see which would produce the most gas pressure. It was a short and normal lab, but it was fun. There was some time between each test, and in that time, I ran through the procedure and took notes. I thought that the soda would have the most gas pressure because it is a carbonated drink, and when it is mixed with yeast, it will most likely have more carbon dioxide and oxygen released than the other mixtures. I ended up being right, because the test with the most gas pressure was the soda (acid) test. It had a pressure of 102.70, and it is lower than normal because the carbon dioxide was released while it was sitting as the final preparations were done. Also, it was high because of the release of carbon dioxide and oxygen from the yeast being added, proving that my hypothesis is correct.

In this image, you can see the Milk of Magnesia (base) test in the red, and the skim milk (neutral) test in the blue. The M of M is the second greatest in pressure value, and the skim milk has the lowest pressure in the end of the test.

In the skim milk mixture (SMM), there was a much lower gas pressure than the other two tests. This is probably because the SMM was neutral, and when mixed with the hydrogen peroxide, it became slightly more acidic but still mainly neutral. Then when mixed with the yeast, there was a much lower reaction compared to the other tests.

I would say that all three tests were successful, but there could've been better results. There was a single problem that was run into. That was the fact that the soda "de-carbonated" from sitting in the graduated cylinder for a minute or two. Other than that, the test was nice and interesting.