How Stevia is Made
The first commercially available steviol glycosides were extracted from the leaves of the stevia plant. In recent years, stevia producers have introduced new methods to help sustainably scale up the production of steviol glycosides that are found in stevia plants in small quantities, such as Rebaudioside M (Reb M).
To date there are four (4) known and approved production technologies to produce steviol glycosides: extraction from the stevia plant, bio-conversion of stevia extract, glucosylation of stevia extract, and fermentation .
Production by Extraction
Steviol Glycosides from the stevia plant are produced from the crushed leaves of the stevia plant and then steeped into hot water. The liquid extract is then filtered and separated from the leaves. The high purity plant extracts are further purified with water and/or food grade alcohol (which, if used, is later removed).
Production by Bioconversion
Bioconversion starts with steviol glycosides extracted from the stevia leaf that are then converted to different targeted steviol glycosides, such as Reb M and Reb D or other unique glycosides with the use of enzymes – Enzymes are derived from genetically modified micro-organisms. Bioconversion mimics the maturation process which naturally occurs within the stevia plant.
Production by Glucosylation
Glucosylation starts with steviol glycosides extracted from the stevia leaf. Glucose units are added by the use of enzyme(s), producing a combination of steviol glycosides. Enzymes may or may not be derived from genetically modified micro-organisms1. Some of these steviol glycosides may or may not be found in the stevia leaf.
Production by Fermentation
Fermentation starts with a genetically modified micro-organism1 that converts sugars into steviol glycosides like Reb M and Reb D or other unique glycosides. Fermentation mimics the process which occurs within the stevia plant in nature.
 All enzymes or micro-organisms are removed from the final product, leaving purified steviol glycosides.