Stevia leaf (Stevia rebaudiana B.) is a sweetener native to Paraguay and Brazil. It has been used by the South Americans to sweeten drinks and food for over 1,500 years. The stevia plant is a perennial herb that can grow up to 2.5ft tall, with small, aromatic leaves and small tubular white flowers. The flowers are often removed to improve the flavor of the leaves. Stevia's flavor lasts longer than that of sugar. It does not ferment and is pH as well as heat stable.

Stevia leaves contain eight glycoside compounds that provide their sweet taste - between 200 and 300 times sweeter than cane sugar. Rebaudioside A (Reb A) is the main glycoside responsible for the sweet flavor of stevia, and does not leave a bitter aftertaste. Aside from glycosides, stevia also contains powerful plant compounds including apigenin, kaempferol and quercetin.*