Blowing Up Balloons with Yeast

Yeast are amazingly talented little organisms.  They make bread, beer, wine, certain dairy products.  Did you know that yeast can also blow up balloons?


Here’s another fun experiment to do with the kids:


Find a small bottle, like a soda or water bottle.  The smaller the bottle, the better your results will be.

Fill the bottle about 1/2 to 3/4 full of warm water.  It should be about the temperature of nice, warm bath water.  If the water is too cold, this will take a long time.  If it’s too warm, it will kill the yeast.

Add some yeast and some sugar (about a tablespoon-ish of each).  Quickly stretch a balloon over the mouth of the bottle, and make it air-tight with some masking tape.  Give the bottle a bit of a splash/shake to help mix it up, and watch and see what happens.  After juts a few minutes, you should see the balloon start to fill up a bit.


What’s happening with this?

Well, the yeast is breaking down the sugar, and using it to get energy.  One of the by-products of this process is Carbon Dioxide.  The Carbon Dioxide is released by the yeast, and fills up the balloon.  That’s also how yeast helps bread rise- by producing air bubbles in the dough.


One response to “Blowing Up Balloons with Yeast

  1. Forwarded this to a couple of the Wagner children.  They now have a summer science project


Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s