Glossary
Decoction mash
A traditional continental method in which part of the mash is removed, boiled and returned, raising the whole mash to the next temperature step.
Pronounced de-COCK-shun.
Also called decoction, double decoction, triple decoction.
The full record
Decoction mash has its own catalogue entry with the detail this page summarises — causes, thresholds, related styles and evidence.
Decoction mash — Raise a mash to its next temperature step by removing part of it, boiling that portion and returning it — the traditional continental method.
Decoction predates reliable thermometers and direct-fired temperature control: boiling a measured portion and returning it is a repeatable way to hit a temperature step without being able to measure one. It also worked well with the undermodified malt of the period.
Boiling part of the mash produces melanoidins, and many brewers hold that this is what gives a traditional Munich Dunkel or Bohemian lager its particular depth of malt character. Whether the effect survives blind comparison with a well-made step mash using modern malt is genuinely contested within the trade, and BeerHQ does not present either position as settled.
Commonly misunderstood
Decoction is often described as necessary for authentic continental lager. Many of the breweries most associated with it have moved to step mashing, and the sensory difference is disputed rather than demonstrated.
Related
- Melanoidin — The compound group credited with decoction’s character.
- Step mash — The modern method that replaced it in most breweries.
- Munich Dunkel — A style traditionally associated with decoction.
More vocabulary
Arrested fermentation · Barrel ageing · Batch sparging · Biotransformation · Blending · Bottle conditioning · Bottom fermentation · Burtonisation · Cask conditioning · Centrifugation
See every term on the glossary index.
Last reviewed 2026-08-16.