If you have ever visited Bruichladdich Distillery one of the things that may have struck you is the sheer variety of whisky casks stacked in and alongside our warehouses. All shapes and sizes from all over the world are gently and slowly maturing our elegant floral single malt on the Atlantic coast on the Rhinns of Islay.
Whisky cask capacity, while originally based on historic and imperial gallon measurements, has evolved and continues to do so with current usage and in different industries.
The thickness of staves varies depending on usage. For example transport quality casks are thicker (more robust) at 27mm.
The casks used in whisky production can be no larger than 700 litres in size. There is no minimum cask size in Scotland, but there are a few standard sizes in use today. These are the casks we use at Bruichladdich:
Madeira Drum 650 litres: Very uncommon in the Scotch whisky industry but used from time to time, mainly for ACEing (Additional Cask Evolution).
Sherry Butt 500 litres: A cask of American oak used for maturing Sherry in the Solera system, and until 1981, for shipping it to the UK. Sherry butts used for transport were also made from Spanish oak, which was abundant and inexpensive.
Port Pipe 500 litres: A cask used for ageing Port, squatter and rounder than a sherry butt
Demi-Muids 500 litres, French or American oak, double-sized hogshead shape.
Cognac Transport 350 litre Cognac casks, Limousin or American oak.
Puncheon 320 litres: A cask constructed from spare staves, shorter and fatter than a butt
Bordeaux Transport 300 litres, French or American oak.
Hogshead 250 litres: A cask size used predominantly in the wine trade. Can be either French or American oak.
Barrique/ Piece 225 litres: The default French cask size for maturing wine. The Burgundian ‘Piece’ is more rounded.
Barrel 195 litres: The default, slim, American oak cask invented for the bourbon industry, the most abundant size used for whisky.
Quarter Cask 80 litres: A small cask recently re-introduced into the industry to age whisky ‘more quickly’. The smaller cask creates a greater ratio of surface area to whisky, so more whisky per litre comes into contact with the oak, creating a stronger, or more rapid reaction.
Bloodtub 50 litres: The smallest viable cask, rarely used these days.
(All cask sizes are approximate. Remember that these are hand-crafted vessels and can vary from cooperage to cooperage. This is why some casks are weighed before and after filling to ensure exact content knowledge).