Why is the U.S. fountain version of Diet Coke sweetened with aspartame and saccharin?
Because aspartame by itself is heat and pH-sensitive (meaning it loses sweetness over time), the concentrated found syrup causes aspartame to lose it sweetness faster than it would in a finished beverage. Fountain diet drinks, therefore, are sweetened with a blend of aspartame and saccharin to assure maximum product quality.
