Ethanol
Ethanol is a type of alcohol that yeast makes when it breaks down sugar.
Yeast cells are small round blobs packed inside a jar of sugar cubes. As each yeast blob eats a sugar cube, it shrinks and releases a tiny liquid drop. Those drops collect at the bottom of the jar as ethanol. The more sugar cubes the yeast eats, the deeper that liquid layer grows.
Explaining ethanol by grade level
When you mix yeast with grape juice, the yeast eats the sugar. It makes bubbles of gas and a bit of alcohol. That alcohol is called ethanol. You can smell it if you sniff the mix after a day.
Projects that explore ethanol
When yeast runs out of oxygen but still has sugar to eat, it switches to fermentation — a process that produces carbon dioxide and ethanol instead of using oxygen. You place dried baker's yeast in a sealed plastic bag alongside the juice from 150 grams of crushed grapes, with a pH strip taped inside to track acidity changes. Over the next hour, gas fills the bag and foam appears.
Ethanol is a type of alcohol that yeast makes when it breaks down sugar. You mix lukewarm water, sugar, and yeast in a plastic bag. The yeast cells eat the sugar and release gas as they produce ethanol.