Stevia is the common name for stevia sweeteners. It is also used to describe the plant. It is a native perennial plant originally found in Paraguay and Brazil. It contains around 10% of stevia glycosides (sweet components) in its leaves. Stevia, in its natural herbal form, is approximately 10 to 15 times sweeter than common table sugar. You can actually eat the leaves but they can leave a bitter menthol-like aftertaste.
Stevia leaves contain 6 stevia glycosides, or sweet components, where each glycoside contains a different level of sweetness. The two main glycosides are Stevioside and Rebaudioside A (RebA). Generally, Steviosides represent 5-10% and RebA represents 2-4% of the dry weight of a stevia leaf respectively.
There are other related compounds including Rebaudioside C (1-2%) and Dulcocide A&C, as well as minor glycosides that are found in very small quantities in the leaf. They are less sweet and also contribute to the bitterness.
A typical stevia extract that combines all 6 glycosides (sweet components) is around 250 sweeter than sugar and has a strong bitter menthol-like aftertaste.
Stevioside is one of the glycosides found in the stevia leaf. Stevioside extract is generally 200-300 times sweeter than sugar but has that bitter menthol-like aftertaste. RebA extract is between 300-450 times sweeter, depending upon the grade, than sugar and is the sweetest compound in the leaf with much less of an aftertaste. Very high grade RebA (the higher the RebA number, the higher the sweetness level), as high as 98% but generally 95-97% is the sweetest of all the glycosides but also comes at a higher cost.
Naturally Sweet Stevia RebA97 and RebA40, are high-intensity sweeteners and as such are not often sold to retail customers in their pure form, unless the customer has had some experience with Stevia previously. Pure Stevia is VERY strong, up to 450 times sweeter than sugar, so for most consumers it is not an option as it is only required in minute quantities for most uses and is therefore also difficult to measure out and handle. We really only recommend pure stevia for experienced stevia users and manufacturers, where the larger volume makes it easier to manage.
However, depending on the application, these products can be easily blended with either fillers and/or bulk sweeteners to improve their day to day usability. This gives Food & Beverage manufacturers and formulators the flexibility for instance to:
- Adjust the sweetness level
- Modify the taste
- Balance out the flavour from other ingredients
Typical fillers and bulk sweeteners include dextrin, erythritol, inulin, lactose, maltitol, maltodextrin, sorbitol and xylitol. Hundreds of preparations containing stevia sweeteners with fillers and/or bulk sweeteners are now commercially available. They are NOT all the same.
For general consumer use, we recommend our Naturally Sweet Blend, which contains RebA98 and erythritol as its filler. It has no bitter menthol-like aftertaste and is much easier to handle with a sweetness ratio of approximately 1:1.