Erythritol
What it does
Bulk sweetener; almost no calories.
How it's made
Made by fermenting glucose.
Erythritol is a sugar alcohol (polyol) used as a bulk sweetener, about 60–70% as sweet as sugar but with almost no calories, making it popular in "zero-calorie" sweeteners and reduced-sugar drinks and foods. Unusually among polyols, it is very well tolerated and much less likely to cause the laxative effect associated with the others.
It is made by fermentation rather than hydrogenation. Glucose, usually from corn starch, is fermented by certain yeasts or fungi that naturally convert it into erythritol, which they release into the broth. This biological route is what distinguishes erythritol's manufacture from the hydrogenated polyols.
The erythritol is recovered from the fermentation liquid, purified and crystallised into a white powder. Because the body absorbs it well but does not metabolise it for energy — it is mostly excreted unchanged in the urine — it contributes virtually no calories and does not raise blood sugar, and its good digestive tolerance and tooth-friendliness make it a favourite in sweetener blends.
Possible reactions
Better tolerated than other polyols, but large amounts can still cause gas; some heart-marker research is debated.