By Harold McGee
Though most of the intensive sweeteners that we consume today were synthesized in industrial laboratories, a number of them occur in nature and have been enjoyed for centuries. Glycyrrhizin or glycyrrhizic acid, a compound found in licorice root, is 50–100 times sweeter than sucrose, and is the reason that licorice was first made into a sweet by extracting the root in hot water, then boiling down the extract. The sweetness of the extract builds slowly in the mouth and lingers. And the leaves of a South American plant commonly known as stevia, Stevia rebaudiana, have been used for centuries in its homeland to sweeten maté tea. Its active ingredient, stevioside, is available in a purified powdered form. Neither it nor the plant has been approved by the U.S. FDA as a food additive, so they’re sold as dietary supplements.