What percentage of wort is typically fermentable?

In brewing, the fermentability of wort generally refers to the proportion of sugars present that yeast can convert into alcohol and carbon dioxide during fermentation. Typically, around 80% of the sugars in a well-prepared wort are fermentable. This percentage can vary based on factors such as the types of grains used, mash temperature, and the specific enzymes acting on the starches to convert them into sugars.

A well-constructed wort using a range of malted grains, particularly those with higher fermentable sugar content (like pale malts), allows the yeast to access a significant amount of fermentable material. When temperature conditions are optimized during the mash process, more starches are converted to sugars, leading to a higher fermentable wort. This is important for brewers as it directly influences the final alcohol content and the flavor profile of the finished beer.

Lower percentages of fermentable wort, such as 50% or 67%, would imply higher residual sugars, which typically result in sweeter and less alcoholic beers. Hence, 80% stands out as the standard for a fermentable wort that balances alcohol production while maintaining desirable flavor characteristics and mouthfeel in beer.