fermentation
High-gravity brewing
Ferment a stronger wort than the finished beer requires, then dilute to sale strength with deaerated water after fermentation.
Also called dilution brewing, high gravity dilution.
What is actually happening
A brewery with fixed vessel capacity can make more beer by fermenting a wort a third stronger and cutting it back afterwards. The same fermenter yields more finished product, and the economics are obvious enough that most large-volume brewing is done this way.
What it changes is real but narrower than the accusation usually implies. Yeast under higher osmotic pressure produces a different ester and fusel profile, so the beer is not identical to the same recipe fermented at sale strength, and the dilution water has to be deaerated or it undoes the brewery’s oxygen control at the last moment.
What it does not do is add water to finished beer as an adulteration. The declared strength is the strength sold, and the dilution happens before packaging as a designed step rather than afterwards as a cheat.
BeerHQ records it because it is the commonest thing said dismissively about large breweries and one of the least commonly understood. Whether a drinker minds is a matter of taste; what it is, is a matter of fact.
Related steps and concepts
- Primary fermentation — The step it modifies.
- Water treatment — Where the dilution water is prepared.
Also at the fermentation stage
Biotransformation · Bottom fermentation · Diacetyl rest · Hop creep · Mixed fermentation · Open fermentation · Pitching · Pressure fermentation · Primary fermentation · Spontaneous fermentation · Top fermentation · Yeast harvesting
See the whole process in order on how beer is made.
Last reviewed 2026-08-16.