Why does grape juice react with baking soda?

When baking soda (sodium bicarbonate, NaHCO3) is added to grape juice, it undergoes a chemical reaction that produces carbon dioxide gas (CO2). This reaction occurs because grape juice contains acids, such as tartaric acid and malic acid, which react with the baking soda to form sodium salts of these acids, releasing carbon dioxide gas in the process.

The chemical equation for this reaction:

NaHCO3 (sodium bicarbonate) + H+ (from grape juice) → Na+ (sodium ion) + H2O (water) + CO2 (carbon dioxide gas)

The net effect of this reaction is the evolution of carbon dioxide gas, which creates bubbles and causes the grape juice to fizz.

This reaction is similar to the one that occurs when baking soda is added to acidic ingredients in baking, such as vinegar or buttermilk, to produce a leavening effect, making baked goods rise.