What is the expected percentage of unfermentable sugars in wort?

The expected percentage of unfermentable sugars in wort is indeed around 20%. Unfermentable sugars, primarily composed of dextrins and certain other complex carbohydrates, contribute to the body, mouthfeel, and residual sweetness of the finished beer.

During the mashing process, enzymes convert starches in the malt into fermentable sugars such as glucose and maltose, while some of the resulting sugars remain unfermentable due to their complex structures. Typically, the final wort will contain roughly 20% of these unfermentable sugars, which play a crucial role in balancing flavor and viscosity in the beer.

Understanding the composition of wort and the fermentation process is essential for brewers, as it directly affects the final characteristics of the beer. Knowing that unfermentable sugars constitute about 20% helps brewers control the sweetness and body of their beers while also informing decisions about yeast choice and fermentation conditions.