Why is sucrose boiled with an acid instead of an alkali?

Answer 1

Hydrolysis breaks the glycosidic bond, converting sucrose into glucose and fructose. Hydrolysis is, however, so slow that solutions of sucrose can sit for years with negligible change. If the enzyme sucrase is added, however, the reaction will proceed rapidly. Hydrolysis can also be accelerated with acids, such as cream of tartar or lemon juice, both weak acids. Similarly gastric acidity converts sucrose to glucose and fructose during digestion.

Answer 2

Sucrose is boiled with an acid instead of an alkali because acids catalyze the hydrolysis of sucrose, breaking it down into its constituent monosaccharides (glucose and fructose). Alkalis could also break down sucrose, but they can cause browning reactions and undesirable flavors in the final product.