Sugarcane Reb M is a zero-calorie sweetener produced by fermenting sugarcane sugar with specially engineered yeast. “Reb M” is short for Rebaudioside M, a molecule found naturally in stevia leaves but only in tiny amounts. Rather than extracting it from stevia plants, manufacturers use sugarcane as a feedstock, converting its sugars into Reb M through fermentation, similar to how beer or wine is made. The result is a sweetener that tastes much closer to real sugar than earlier stevia products, without the bitter aftertaste many people associate with stevia.
How It Differs From Regular Stevia
The stevia sweeteners that have been on shelves for years are mostly based on a compound called Rebaudioside A (Reb A), which makes up 2 to 4 percent of the dried stevia leaf and was the first steviol glycoside produced commercially. Reb A is intensely sweet, but it comes with a lingering bitter aftertaste that turns many consumers off. That bitterness is the main reason some people say they “don’t like stevia.”
Reb M belongs to the same family of steviol glycosides but has a noticeably cleaner taste. Sensory research confirms that Reb M has no bitter aftertaste, and trained taste panels have found that blending Reb A with Reb M significantly reduces the bitterness scores of stevia-sweetened products like ice cream. In consumer acceptance tests, those blends consistently score higher in overall liking compared to Reb A alone.
Why Sugarcane Instead of Stevia Leaves
Reb M exists naturally in stevia leaves, but in vanishingly small quantities. Extracting meaningful amounts from plants would require enormous acreage and processing, making it impractical for large-scale production. Fermentation solves that problem. Manufacturers feed sugarcane syrup to a strain of baker’s yeast (Saccharomyces cerevisiae) that has been engineered to produce the enzymes needed to build Reb M molecules. The yeast consumes the sugar, biosynthesizes Reb M internally, and excretes it into the fermentation broth, where it’s collected and purified.
The process is conceptually the same as brewing: yeast eats sugar and produces a target compound. The difference is that instead of alcohol, these modified yeast strains output a sweetener. Because the starting material is cane sugar, you’ll sometimes see the product marketed as “sugarcane-derived” or “made from sugarcane,” even though the final molecule is identical to what’s found in stevia leaves.
Calories and Blood Sugar Effects
Reb M is treated as non-caloric in nutritional research. In metabolic studies, researchers assign it zero calories per gram, compared to about 3.75 calories per gram for table sugar or fructose. That makes it useful for people managing their weight or calorie intake.
Its effects on blood sugar are also favorable. In animal studies, mice fed a high-fat diet along with Reb M did not show worsened metabolic markers compared to controls. Fasting glucose levels trended lower in groups receiving steviol glycosides, though the improvements in insulin sensitivity didn’t reach statistical significance under all conditions. Broader research on steviol glycosides has shown more encouraging results in humans: in one study of 20 volunteers with type 2 diabetes, consuming stevia compounds for 60 days produced a significant decrease in both fasting and post-meal blood glucose levels.
Steviol glycosides also appear to interact with a channel in the body that facilitates insulin release from pancreatic cells, which may partly explain the glucose-lowering effects seen in some studies.
How It Appears on Labels
If you’re scanning ingredient lists, sugarcane Reb M can show up under several names. The FDA recognizes it as “stevia sweetener,” with approved synonyms including “steviol glycosides rebaudioside M,” “Reb M,” and the trade name EverSweet. Some brands list it simply as “stevia leaf sweetener” or “steviol glycosides,” which can be confusing since the molecule was made by fermentation rather than leaf extraction. The FDA permits this because the final compound is chemically identical to the plant-derived version.
Regulatory Status
Fermented Reb M holds Generally Recognized as Safe (GRAS) status with the U.S. FDA, which has issued no objections to its use as a general-purpose sweetener in foods and beverages. This approval covers steviol glycosides at 95 percent purity or higher, whether they come from stevia leaf extraction, enzymatic bioconversion, or microbial fermentation. The European Food Safety Authority (EFSA) has also evaluated fermented Reb M produced by different yeast strains for safety.
Who Makes It
A handful of companies dominate production. Amyris, a biotechnology firm based in the San Francisco Bay Area, developed one of the first commercial fermentation processes for Reb M using sugarcane syrup. The company partnered with ASR Group, the cane sugar refiner behind Domino Sugar and C&H Sugar, which agreed to purchase 80 percent of Amyris’s sweetener output. In Brazil, Amyris worked with cane sugar producer Raízen on manufacturing.
Cargill and DSM formed a joint venture called Avansya to produce both Reb M and a related compound, Reb D, at a facility in Blair, Nebraska. Smaller players include Manus Bio and Blue California, both of which have fermentation capabilities for steviol glycosides. The competitive landscape has pushed prices down over time, making Reb M increasingly common in mainstream food and beverage products where clean, sugar-like sweetness without calories is the goal.
Sweetness and Practical Use
Like other steviol glycosides, Reb M is hundreds of times sweeter than table sugar by weight, so only tiny amounts are needed in formulations. This extreme potency is why you’ll often see it paired with bulking agents like erythritol or allulose in consumer packets and baking blends. On its own, Reb M would be far too concentrated to measure with a kitchen spoon.
Its clean taste profile makes it especially suited to products where bitterness is hard to mask: flavored waters, dairy, protein shakes, and baked goods. The ice cream research is a good example of its practical value. When food scientists replaced part of the Reb A in ice cream formulations with Reb M, bitterness dropped measurably at both immediate tasting and after 90 seconds, the point where stevia’s aftertaste is most noticeable. Consumer liking scores rose accordingly. For manufacturers, that means a stevia-sweetened product that people actually want to eat again.