Glossary
Barrel ageing
Maturing beer in wooden barrels, either for the wood and spirit character they contribute or for the microflora they harbour.
Also called barrel aged, wood ageing, barrel-aged.
The full record
Barrel ageing has its own catalogue entry with the detail this page summarises — causes, thresholds, related styles and evidence.
Barrel ageing — Mature beer in wooden barrels for the wood and spirit character they contribute, or for the microflora they harbour and the slow oxygen exchange they allow.
Two quite different practices share the name. Fresh spirit barrels — bourbon, rum, sherry — contribute vanillin, coconut lactones, tannin and residual spirit, and are used for strong dark beer over months. Neutral or foeder-scale wood is used in Belgian and Flemish brewing as a home for microflora and for slow, controlled oxygen exchange over years.
Barrels are not sterile and are not intended to be. In the second tradition that is the point.
Related
- Foeder — The large-format vessel used in Flemish brewing.
- Brettanomyces — The organism wood commonly harbours.
- Imperial stout — The style most associated with spirit-barrel ageing.
More vocabulary
Arrested fermentation · Batch sparging · Biotransformation · Blending · Bottle conditioning · Bottom fermentation · Burtonisation · Cask conditioning · Centrifugation · Cold break
See every term on the glossary index.
Last reviewed 2026-08-16.