Fermentable vs. Non-Fermentable Sugars: What Every Brewer Should Know

Understanding the difference between fermentable and non-fermentable sugars is key to predicting final gravity, sweetness, and body. Fermentable sugars (glucose, maltose, sucrose) are consumed by yeast, lowering gravity and increasing alcohol. Non-fermentable sugars like dextrins remain in the beer, contributing to body and residual sweetness.

Each sugar type plays a role. Maltose provides the bulk of fermentable content. Glucose is rapidly fermented, while dextrins offer mouthfeel without increasing ABV. Overuse of non-fermentables can lead to cloying sweetness, while too few can result in thin, dry beer.

Accurate sugar testing with tools like the Beer-o-Meter helps brewers tailor sugar profiles. This allows for better control of the final product, especially for styles like stouts and Belgian ales that rely on a careful balance of sweetness and body.