Serving custom · United Kingdom
Cask cellar service
Cask beer arrives alive and unfinished, and the pub has to settle it, vent it, tap it and sell it within days — which makes a British cellar a small production facility.
The cask is not a container of finished beer. Fermentation is still completing inside it, so the pub receives a live product and the last stage of production happens under the bar. That is the single fact from which every British cellar practice follows.
A cask is stillaged on its side and left to settle, often for a day or more, so that yeast and finings drop to the belly. A soft porous spile is then driven into the shive to let excess carbon dioxide escape — venting — and swapped for a hard spile to hold condition once the beer has quietened. A tap is driven into the keystone at the end, and the beer is drawn from there.
Dispense is by gravity straight from the cask, or through a beer engine: a hand pump that pulls beer up from the cellar by suction, with no gas pushing it. A sparkler, a perforated nozzle on the swan neck, forces the beer through small holes and knocks carbonation out of it into a dense creamy head. Northern practice generally uses one; southern practice generally does not, and the same beer is a genuinely different drink either way.
The cost of all this is real and should be said. A tapped cask has a working life of a few days, and cask beer kept badly is unpleasant in a way keg beer is not. The format’s virtues and its fragility are the same property seen from two sides.
How it works
Stillage and settle
The cask is placed on its side on a stillage and left, usually for at least a day, so yeast and finings drop clear of the tap line.
Vent with a soft spile
A porous peg is driven into the shive so surplus carbon dioxide from the continuing fermentation can escape rather than over-carbonating the beer.
Harden up
Once the beer has stopped working hard, the soft spile is replaced with a non-porous hard one to hold the remaining condition in.
Tap the keystone
A tap is driven through the keystone in the cask head in one clean blow. Hesitating is what sprays beer across the cellar.
Serve within days
Air replaces the beer drawn off, so an opened cask oxidises. Three days is a common working limit and the last pints of a slow cask are noticeably tired.
What it does
BeerHQ’s rule for anything ritual: name the mechanism or say it is convention. These are the mechanisms.
- Venting controls carbonation directly: a cask left unvented builds pressure and pours foam, and one left open too long goes flat.
- A beer engine moves beer by suction rather than gas pressure, so nothing is added to the beer and the carbonation in the glass is only what the cask made.
- A sparkler mechanically drives carbon dioxide out of solution, producing a dense head and a softer, less prickly palate — the north–south difference is a real change to the drink, not a garnish.
- Cellar temperature around 11–13 °C is chosen because the malt and hop aromatics that cask beer is built on are largely suppressed below about 8 °C.
What you will hear
- spile
- A small peg driven into the shive. Soft and porous to vent gas, hard and solid to hold condition.
- keystone
- The wooden or plastic bung in the cask head that the tap is driven through.
- stillage
- The frame the cask rests on, holding it steady and tilted so it can run out clear.
- sparkler
- A perforated nozzle on the end of a swan neck that knocks carbonation out and builds a tight creamy head. Standard in the north of England, generally rejected in the south.
What people get wrong
Cask ale is served warm.
It is served cool — around 11–13 °C, against 3–5 °C for a mass-market lager. The temperature is chosen because the aromatics the beer is built on disappear below roughly 8 °C, not because anybody prefers warm beer.
A hand pump means the beer is pumped up with gas.
A beer engine is a suction pump. It lifts beer from the cellar by drawing it, with no gas in contact with the beer, which is exactly the distinction CAMRA’s definition of real ale turns on.
Questions
What is a beer engine?
The hand pump on a British bar. It is a suction pump that draws beer up from the cellar by lever action, with no carbon dioxide pushing it, so nothing is added to the beer between cask and glass. That absence of applied gas is the technical core of what CAMRA means by real ale.
What does a sparkler do?
It is a perforated nozzle fitted to the swan neck that forces beer through small holes under pressure, knocking dissolved carbon dioxide out of solution. The result is a dense creamy head and a softer, less sharp palate. Northern English practice generally uses one and southern practice generally does not, and the same beer genuinely tastes different either way.
The beers it is performed on
- Ordinary bitter
The everyday British cask ale: low in strength, gently bitter, and built to be drunk in pints over a whole evening.
- Best bitter
A step up from ordinary bitter in strength and depth, with more malt body while staying firmly sessionable.
- Dark mild
A low-strength dark British ale, gently sweet and nutty, built for drinking in quantity after physical work.
Connected
The room: The British pub · Free house
The dispense: Cask, hand-pulled · Cask, gravity-dispensed
Last reviewed 2026-08-29.