Glossary · Equipment
Cask
Also written barrel. Each is a name for the same thing, which is why none of them has an entry of its own.
Definition
A wooden vessel of staves bound by hoops, bulging at the middle so it can be rolled and turned. Casks both store cider and shape it, admitting a slow ingress of oxygen through the wood.
- Subject
- Equipment
- Also written
- barrel
In more detail
Traditional cider casks were often second-hand from the spirit and wine trades and were valued as neutral containers rather than as flavouring. Their porosity means constant slow evaporation, so a cask must be kept topped up, and their surface harbours a microflora that cleaning cannot remove.
Where this is covered properly
The glossary defines; these pages explain. Each is described in its own words.
Related terms
Terms that belong to the same part of the subject, or that this one is routinely confused with.
Fermentation
Barrel ageing
Maturing cider in wood, either in neutral casks used purely as vessels or in barrels chosen to contribute oak, spirit or wine character.
Equipment
Hogshead
A cask size long used for cider. Cask sizes were never fully standardised across trades and regions, and a cider hogshead was not necessarily the same volume as a beer or wine one.
Equipment
Shive
The wooden or plastic plug driven into the bung hole on the belly of a cask, carrying a smaller central section through which a spile can be pushed to vent gas.
Equipment
Keystone
The small plug set into the end of a cask, through which a tap is driven when the cask is put on to serve.
Equipment
Bung
The stopper closing the filling hole of a cask or vat. During fermentation it is left loose or replaced by an airlock; afterwards it is driven home to exclude air.
Fermentation
Ullage
The empty space between the surface of the cider and the top of its container, and by extension the volume lost that creates it. Ullage in a maturing cask is where oxidation and acetification start.
Fermentation
Topping up
Refilling a maturing vessel with similar cider to eliminate the headspace, so that no air surface remains for oxidative and acetic spoilage.
Where to go next
- Cider glossary — The whole vocabulary, by subject and A–Z.
- Comparisons — Terms that are only really clear when set against the thing they are not.
- Search — Finds terms by their aliases and by their spellings in other languages.
Sources
What this page rests on. Where a source is marked as registered rather than read, CiderHQ is recording that the body is authoritative on the subject without claiming to have worked through the document itself. See our evidence policy for what each state means.
Hereford Museum of Cider collections and interpretation
Hereford Cider Museum Trust · museum · retrieved 2026-08-24
Somerset Rural Life Museum — cider collections
South West Heritage Trust · museum · retrieved 2026-08-24
Cider and perry production technical training material
Peter Mitchell / Cider and Perry Academy · reference work · registered as competent for this subject
Searched again on 2026-08-25 and it remains the one printed source here that a bibliographic check cannot fix, because it is not a published work with an edition. It is course material issued to participants of a training programme, so there is no catalogue record to verify, no ISBN, and no lawful public copy. Its state stays `registered` for that reason rather than through inattention.