cooling
Wort chilling
Cool boiled wort rapidly to pitching temperature, producing a good cold break and passing quickly through the range in which spoilage organisms thrive.
Also called knockout, heat exchange.
What is actually happening
A plate heat exchanger brings wort from boiling to pitching temperature in a single pass, which is both fast and efficient — the heat removed is usually recovered into the next brew’s liquor.
Rapid cooling produces a better cold break, because proteins that would remain dissolved on slow cooling precipitate sharply. Slow cooling also leaves wort for hours in the 20–40 °C range where contaminants establish most readily.
Typical conditions
| Temperature | 8–22°C |
|---|---|
| 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.
- DMS — A cooked-vegetable note from a malt precursor that a vigorous open boil should have driven off.
- Infection — Unintended microbial growth — which is a fault only because it was unintended, since the same organisms define lambic.
- 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
- Pitching — What follows.
- Cold break — What rapid chilling produces.
Also at the cooling stage
Coolship inoculation · Wort oxygenation
See the whole process in order on how beer is made.
Last reviewed 2026-08-16.