How about a puppy, Mommy? Please oh please oh please oh please…Or a kitten? A horse? Goat?
No, no, no, and no. There will be no more pets in this house. We have a python, a beta fish, and two aquatic frogs (blog post coming soon on the science of caring for these animals – stay tuned!). But, if you are really insistent on getting a pet in the house, I am willing to be flexible: we can make yeast pets.
Yeast pets? What is that? Well, to be honest, it is just yeast, but in this fun at-home science experiment, you can talk with your kids about how we know yeast is alive, see evidence of that living activity, and turn the dry powder in the baking cabinet into something that my children have dubbed, “yeast pets.”
Here’s how it works: Yeast is a fungus, which is actually a living organism. It doesn’t look like it is alive, because the yeast that we buy in the supermarket is dried out, or in a form called a spore. In this spore form, the yeast can survive dry, without food or water, for extended periods of time.
We can move the yeast out of its spore form by adding warm water (not too hot, though, that will kill the yeast), and sugar, which is the food that the yeast needs to grow. When we bake bread, this is what is normally done prior to adding the yeast to the flour, to make sure that the yeast “comes back to life” and will help the dough rise. Instead of doing it for bread making in this case, we can mix the yeast, warm water, and sugar in a small plastic water bottle and cover the top with a balloon.
What happens next? The balloon will slowly inflate. This occurs because as the yeast grows and consumes the sugar, it releases a gas called carbon dioxide. That gas causes the balloon to inflate. The more yeast and sugar you add, the bigger the balloon will grow!
Check out some detailed instructions for this experiment HERE, and the first four parts of this series on fun science activities to do with kids (ONE, TWO, THREE, and FOUR). More next time, scientists! Have a great day!