Yeast is the living organism that helps your favorite baked goods rise. The word yeast comes from the Sanskrit “yas,” which means to boil or seethe. This ivory colored, one-celled fungus requires warmth, food and moisture to work its magic. You can teach your youngster how yeast works in baking with the use of a simple experiment that lets him see the yeast in action.
Tear open a packet of dry yeast. Pour the contents of the packet into a large bowl. Explain to your child that the dry yeast from the packet is in an inactive or “sleeping” state.
Add 1 tsp. of granulated sugar to the yeast. Pour 1/4 cup of warm water over the sugar and yeast. Explain that when you add liquids, such as water or milk to your baking recipe, the yeast begins to wake up.
Continue to observe the yeast in the bowl for the next 10 minutes. When bubbles start to appear, explain that the yeast has awakened from its inactive state.
Watch the yeast as it continues to bubble and expand and tell your child that the yeast eats the sugars that you add to your baking recipes. The bubbles that the yeast creates after eating the sugar are actually carbon dioxide.
Wrap up the experiment with an explanation that as the yeast continues to consume the sugar, it creates more carbon dioxide. It's this carbon dioxide that causes your baked goods to rise, becoming fluffy in nature.