pin

A pin is a wooden cask used in breweries and distilleries to store and transport beer, ale, or spirits. It holds exactly half the volume of a firkin, making it one eighth of a standard barrel. In imperial measure, a pin contains 4.5 gallons or 20.5 litres. The term persists in British brewing despite modern use of metric units and steel containers.

The pin sits in a hierarchy of traditional cask sizes that reflects centuries of trade practice. A barrel holds 36 imperial gallons; a hogshead holds 54 gallons; a firkin holds 9 gallons; and a pin holds 4.5 gallons. Below the pin come the kilderkin at 18 gallons and the barrel itself at the top. These ratios were standardised under the Assize of Ale, medieval English law that regulated beverage measures. Brewers still reference these sizes when specifying orders and shipments, even though many now work in hectolitres.

Physical form and construction

A pin is built like any traditional wooden cask: vertical wooden staves bound with metal hoops, with a barrel-shaped profile wider at the middle than at the ends. The staves are typically oak, and the hoops are steel. Pins are smaller and lighter than firkins, making them easier to handle in confined spaces such as pub cellars or brewery storage rooms. A full pin weighs roughly 60 pounds when filled with liquid, within the range a worker can roll or carry safely.

The cask must be sturdy enough to withstand the pressure of carbonated beer and to survive repeated filling, emptying, and transport. Unlike modern kegs with spigots, pins are sealed with wooden bungs driven into a bunghole at the top. Drawing liquid requires tapping in a shive, a wooden peg with a hole drilled through it, or using a cask breather valve in climate-controlled cellars. Wooden pins impart character to beer through slow oxygen exchange and wood contact, which some brewers prize; others prefer the consistency of stainless steel.

The pin remains in use primarily in the United Kingdom and countries with strong British brewing traditions, though its numbers decline as cask ale distribution shrinks. Large breweries have moved to kegs and cask breather systems; smaller breweries and some real ale producers still age and ship in pins and firkins. The term appears on invoices, storage manifests, and in conversations between draught installers and publicans, anchoring the beer trade to its pre-industrial past.