Understanding the Green Source
At its origin, stevia is a leafy, herbaceous green plant known as Stevia rebaudiana. For centuries, indigenous peoples in Paraguay and Brazil have used its leaves to sweeten foods and medicines. When a home gardener or herbalist simply harvests, dries, and grinds the stevia leaves, the resulting product is a bright green powder. This form is the least processed and contains all the plant compounds, including the green chlorophyll, which gives it its distinct color.
The Characteristics of Green Stevia
- Flavor Profile: Green stevia has a more herbal, slightly licorice-like taste and a more potent, sometimes bitter, aftertaste than its white counterpart. The flavor is robust and earthy, reminiscent of the whole plant.
- Nutritional Value: Because it is less processed, some enthusiasts claim it contains more of the plant's natural nutritional components. It is less concentrated and therefore requires different usage amounts than the refined white extract.
- Use Cases: This form is less common in commercial products but can be purchased as a supplement. It works well in teas and smoothies where the herbal undertones are complementary.
The Journey to White: Stevia Extract
Most stevia products found in mainstream grocery stores, whether in packets, drops, or baking blends, are not green but white. This is because they are made from a high-purity stevia leaf extract, which is the result of a multi-step purification process. This process isolates the intensely sweet steviol glycoside compounds, leaving behind the green plant matter and unwanted flavors.
The Extraction and Purification Process
To create the white extract, a process similar to brewing tea is used. The steps typically include:
- Harvesting and Drying: Stevia leaves are harvested and dried.
- Hot Water Extraction: The dried leaves are steeped in hot water to dissolve the sweet steviol glycosides.
- Filtration and Purification: The liquid is filtered to remove the leaves and other plant solids. Further purification steps, often involving water and/or food-grade alcohol, are used to isolate the sweet compounds.
- Decolorization and Crystallization: Specialized processes are used to remove the green and brown pigments, leaving a clear or white liquid. The sweet extract is then dried into a crystalline powder.
This extensive purification results in a white powder that is hundreds of times sweeter than sugar and has a cleaner taste profile, though some may still detect a slight aftertaste.
Comparing Green and White Stevia
The fundamental differences between green and white stevia come down to processing, taste, and purity. Here is a quick comparison:
| Feature | Green (Whole Leaf) Stevia | White (Purified Extract) Stevia |
|---|---|---|
| Color | Green | White |
| Processing Level | Minimal (dried and ground) | High (extract and purify) |
| Purity | Contains all leaf components | Isolated steviol glycosides (e.g., Reb A, Reb M) |
| Taste Profile | Herbal, licorice-like, some bitterness | Clean, sweeter, less aftertaste (in high-purity forms) |
| Sweetness | Less concentrated than purified extract | Extremely potent (200-350x sweeter than sugar) |
| Common Form | Powdered leaf | Powder, granules, liquid drops |
| Regulation | Sold as a dietary supplement | Approved as a food additive (GRAS in U.S.) |
Not All White Stevia is Equal: The Blends
It is important to note that many commercially available white stevia products are not pure stevia extract. The intense sweetness requires only a tiny amount of the extract, making it difficult to measure for home use. Therefore, manufacturers often combine the high-purity extract with fillers or bulking agents to make it easier to measure and to reduce any lingering aftertaste.
Commonly added fillers include:
- Erythritol (a sugar alcohol)
- Dextrose (a simple sugar)
- Maltodextrin (a carbohydrate)
While pure stevia extract does not impact blood glucose, the added fillers in blended products may have an effect, especially for individuals with diabetes. Always check the ingredients list to know what's in your sweetener.
Conclusion
So, is stevia white or green? The answer is both, but the color indicates its level of refinement. The green powder is the raw, dried leaf, while the white powder is the highly purified extract of its sweet components. The processing to create the clean-tasting white extract is what strips away the natural green color and other flavor compounds. For consumers, the choice between green and white stevia depends on personal preference regarding taste, purity, and the specific application, from a simple cup of tea to more complex baking. For more information on stevia and its safety, check resources like the International Food Information Council (IFIC).
