conditioning
Conditioning
Mature beer after primary fermentation so flavours settle, harsh young compounds are cleared and carbonation reaches equilibrium.
What is actually happening
Yeast continues working at low level, scavenging oxygen and reducing acetaldehyde and diacetyl. Proteins and polyphenols complex and settle. Dissolved CO₂ comes to equilibrium with the headspace.
The same underlying process runs under several names — lagering, cellar conditioning, cask conditioning, bottle conditioning — differing in temperature, duration and whether it happens in tank or in package.
Typical conditions
| Duration | 1–12 weeks |
|---|---|
| Scale | Used at both homebrew and commercial scale |
Ranges, not targets. These describe what is usual across the styles and breweries that use this step, and a value outside the range is a decision rather than an error.
What goes wrong here
Risks rather than certainties. This step does not cause these faults; getting it wrong can.
- Acetaldehyde — A green-apple note indicating beer served before fermentation finished — the classic sign of a rushed product.
- Diacetyl — A buttery compound with a very low threshold — normally a sign of rushed fermentation, but traditional at trace levels in some Czech lagers.
- Chill haze — A temperature-dependent haze from protein and polyphenol binding — cosmetic only, and by definition it clears as the beer warms.
Related steps and concepts
- Lagering — The cold, extended form.
- Cask conditioning — The form completed in the pub cellar.
- Bottle conditioning — The form completed in the package.
Also at the conditioning stage
Barrel ageing · Blending · Cask conditioning · Cellar conditioning · Dry hopping · Freeze concentration · Lagering
See the whole process in order on how beer is made.
Last reviewed 2026-08-16.