Yeast Balloon Blow Up to Demonstrate Bacteria Multiplying at Room Temperature

As part of our discussion on food borne illness, I did an experiment to demonstrate how bacteria multiplies at room temperature.  I got the idea from FightBac.org resources which I told you about yesterday.  I also show it with my Safety and Sanitation Power Point and Numbers to Know Prezi.

Some modifications for this time around...

• I didn't mess with the bowls of water.  I simply left one bottle at room temperature and put one in the fridge.
• I had no sugar so I used corn syrup.  It's a good reminder for students to see what they are drinking in soda!
• I mixed the ingredients right in the bottle instead of messing with a separate beaker.

We observed the bottles at 10 minutes:

20 minutes:

Thirty minutes:

And 45 minutes.

Because bacteria are invisible it is great to have such a visual reminder of the importance of cooling food quickly!