About

Ok so this little experiment was a lot of fun for me.  I always think things like this are cool, does that make me a nerd?  I guess, but who cares.  Anyone can blow up a balloon using their mouth, especially me because I’m full of hot air, or so I’m told.  What is really cool is using yeast to blow up balloons, then you know you are awesome, and that’s exactly what we did.

Yeast is a little single cell fungus, or fungi if there are a bunch.  Reminds me of a good  joke.

“A mushrooms asks a flower on a date, she says “No”.  He says ” Aw, but I’m a fun guy.”” hahahahaha.  I know it’s cheesy but it’s funny.

Anyway, yeast are really cool because they break down sugars in a process known as fermentation.  In this process the yeast break down the sugars for their own growth and releases two bi-products: carbon dioxide and ethyl alcohol.

Testing to make sure the water is warm

In bread making the yeast breaks down the complex sugars in the flour (starches) and releases carbon dioxide in to the tiny air pockets in the bread.  This process inflates the bread (rising as we call it) and gives a fluffier and softer consistency to the bread.

If it weren’t for yeast we’d just get saltines I guess.  Thanks yeast.

I’m full of hot air

The yeast we use for bread is a specific yeast that does a very good job of producing carbon dioxide.  There are also wild-yeasts that’s spores (seeds) are airborne.  These we will use another time to make vinegar.

Experiment

Equipment

  • 20 oz bottle (preferably Diet Dr Pepper, because I trust people who drink it)
  • 3 cups warm water (should be just slightly warm to you)
  • 1/4 cup sugar
  • 1 package active dry yeast
  • 1 balloon

So this entire project cost me a grand total of $4.00.  That is including my diet Dr Pepper (DDP for those in the know).  I got balloons at the dollar store and the yeast is about $1.50 at the grocery store.   Most likely you have most of this stuff around your house.

Add Sugar

Shake shake shake

This is 3 part project that is very simple.

  1. Mix the water and sugar in the bottle and shake it up to mix the sugar in.   The kids love this part.
  2. Add the yeast and shake a little more.
  3. Stretch the balloon over the open bottle mouth (I blow up the balloon first to show the kids that I make carbon dioxide too).  Place the bottles in a warm place.  Then wait.

Add Yeast

Patiently waiting

The yeast will begin rather quickly (within like 5 min for us) to produce carbon dioxide.  In fact the mixture will become very bubbly and you will see the balloon start to stand up right within 10 min.

10 min in

After about 1 1/2 hrs the balloon will be quite full.

About 45 min in

Draw a smiley face on the balloon and tie up the yeast balloon to play with.

1 1/2 hours in

Hopefully this little experiment will help your little ones understand how yeast makes your bread softer.  I like to take a piece of bread after and show the air pockets and explain how those are like tiny balloons in the bread that the yeast blew up.  I know my little foodie doodies were really excited for their PBJ after this.