Erythritol is a sugar alcohol that occurs naturally in small amounts in fruits, vegetables, and fermented foods, but the erythritol you buy in stores is made through an industrial fermentation process. Yeast converts simple sugars, typically derived from corn starch, into erythritol in large vats. The process is similar in concept to brewing beer, though the end product is a white, crystalline sweetener with about 70% of sugar’s sweetness and nearly zero calories.
Erythritol in Nature
Erythritol shows up naturally in grapes, mushrooms, and various other fruits and vegetables, though only in trace amounts. Fermented foods contain somewhat more: Japanese sake, wine, and soy sauce have concentrations between 0.015% and 0.091%, while miso bean paste contains around 0.13%. Your body also produces small amounts of erythritol on its own through normal metabolic pathways.
Extracting erythritol directly from these natural sources isn’t practical because the concentrations are so low. You’d need enormous quantities of fruit or fermented food to yield even a small amount. That’s why virtually all commercial erythritol is made through fermentation instead.
How Commercial Erythritol Is Made
The starting material is usually corn starch, which gets broken down into glucose (simple sugar). This glucose is then fed to specialized yeast in large fermentation tanks. The yeast species most commonly used include Moniliella pollinis and Yarrowia lipolytica, both of which are osmophilic, meaning they thrive in high-sugar, high-salt environments. Manufacturers add salt to the fermentation tanks to create these conditions, which pushes the yeast’s metabolism toward producing erythritol rather than other byproducts.
The fermentation typically runs for several days. Under optimized conditions, some strains can produce nearly 100 grams of erythritol per liter of fermentation broth. Researchers have also experimented with cheaper feedstocks like molasses and crude glycerol to bring production costs down, and a pilot plant using corn as its initial sugar source has been operating at industrial scale since 2013.
From Fermentation Broth to White Crystals
Once fermentation is complete, the liquid broth contains erythritol mixed with yeast cells, residual sugars, and other impurities. Getting from that murky liquid to the pure white crystals in your pantry takes several steps.
First, the yeast cells are removed through centrifugation or membrane filtration. The remaining liquid then passes through activated carbon and other filtering materials to strip out color, odor, and dissolved impurities. Some manufacturers use ion exchange chromatography for further purification, similar to how water softeners work.
The purified liquid is then evaporated to concentrate the erythritol, which triggers crystallization. The crystals are separated out, washed, dried, and sieved to achieve a uniform size. The final product is the granulated or powdered erythritol sold as a tabletop sweetener or used as an ingredient in sugar-free foods.
What Happens When You Eat It
Erythritol behaves differently from other sugar alcohols in your body. About 90% of what you consume is absorbed quickly through the small intestine and enters your bloodstream. Unlike sugar, though, your body doesn’t break it down for energy. Instead, roughly 90% of the absorbed erythritol passes through your kidneys and is excreted in urine within 24 to 48 hours, essentially unchanged.
The remaining 10% that isn’t absorbed in the small intestine moves into the large intestine, where gut bacteria may partially ferment it. This is a much smaller unabsorbed fraction than other sugar alcohols like xylitol or sorbitol, which is why erythritol is far less likely to cause the bloating and digestive discomfort those sweeteners are known for.
Regulatory Status
Erythritol holds Generally Recognized as Safe (GRAS) status with the FDA. Cargill, one of the major producers, received a formal “no questions” letter from the FDA in 2019 for using erythritol across a wide range of food categories, including baked goods, beverages, dairy products, candies, jams, snack foods, and sugar substitutes, at concentrations ranging from 3% to 99%. It is approved for use in over 60 countries worldwide.