Notes from Janice’s Desk
Wild purple grapes grow in our area. My family loves wild grape jelly. I often pick and cook the grapes, separate the juice, and then store the juice to use later. If I plan to use the juice in a short time, I store it in the refrigerator. Even with the cold temperature, I have had the juice to ferment. This happens because yeast on the fruit or from the air mixes with the juice. Fermentation is the chemical reaction in which sugar is changed into alcohol and carbon dioxide. Yeast is necessary for this reaction to occur. Yeast is a living organism that feeds on sugar. In other words, fermentation is the chemical change as a result of the digestion of sugar by yeast. The sugar the yeast feeds on is in the grape juice. When fermentation occurs, the carbon dioxide forms bubbles of foam on the surface of the liquid and the gas escapes when the bubbles break. The alcohol remains in the juice. If the reaction continues long enough the grape juice changes into wine. The cold temperature of the frig slowed the reaction so my grape juice had a small amount of alcohol in it. I make jelly with it and after the cooking process most if not all of the alcohol boiled away.
See FERMENTATION for a fun activity.
See FERMENTATION RESEARCH for more information.
Words to Know
carbon dioxide gas