This is a great way to show kids how germs are in our food and “see” the need to refrigerate our food to limit bacterial growth. This traditional kids science experiment is great for home or in the classroom. Seeing how the bacteria grows is a good foundation for a bacteria science fair project.
Simple Germ Experiment for Kids
Let’s see how bacteria grows in food with this easy kitchen science experiment for kids of all ages.
Related: More Science Fair Project ideas for kids
Supplies Needed for Germ Experiment
- 2-3 glass soda bottles
Instructions for Bacteria Science Experiment
Related: Use our scientific method steps worksheets for kids
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.
- The other went onto the counter near the oven at room temperature.
Science Discussion: 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.
More Fun Science Experiments & STEM Activities from Kids Activities Blog
- Make art with a baking soda and vinegar reaction!
- Fun science experiments for kids…it is playful science!
- Have leftover soda bottles? Try this soda bottle craft.
- Coke experiments for the science fair…
- Or a whole bunch of fun science fair project ideas for kids of all ages.
- Egg in vinegar experiment for kids.
How did your germ growth experiment turn out?