This activity is super high interest and fully engaging. . I will post directions in a giant packet-o-science-fun soon. Kids get to work in groups to examine what food yeast likes most. You will need yeast packets, empty water bottles, three different types of "yeast food," hot water and balloons. Add the ingredients into the bottles, and let the race begin!
As the yeast eats, it will release carbon dioxide as waste. This waste product creates carbon dioxide bubbles and will cause the balloons to fill up. The better the food, the faster and fuller the balloon will rise! It takes about 15 to 20 minutes to see any real yeast action but kids LOVE watching the balloons grow!