The standard gauge by which the fermentable and fermented sugars are measured in wort and beer, respectively, is the degree of attenuation. This is understood as the number which expresses to what degree the extract initially present in the wort (original gravity) has been consumed through fermentation.
The limit of attenuation represents the maximum amount of fermentable extract available in wort.
The degree of attenuation in the green beer indicates how much extract has been fermented by the end of primary fermentation.
The degree of attenuation in the finished beer specifies how much extract has been fermented by the end of maturation and lagering.
Determination of the maximum amount of fermentable extract in wort and beer
wort, beer
Yeast is added to (boiled) wort or beer in an Erlenmeyer flask and allowed to ferment completely under constant agitation. The limit of attenuation is calculated from the difference between the extract content prior to (original gravity) and after fermentation. [1, 2]