We learned about germs in food by using yeast growth. First we drank two sodas. This might have been the kids favorite part of the experiment. When else do they get to drink soda at 10am?
We dropped one teaspoon of yeast into each bottle, then we filled each halfway full of warm water and put a balloon on top. One bottle went into the fridge, and one went onto the counter near the oven.
We talked about how the yeast would act as bacteria would, if the balloon blew up, then the yeast was growing.
When we got home, the balloon on the counter had blown up, but the one in the fridge hadn't blown up at all. We are going to watch it a few more days to see what happens.