A Guide to Whisky Cask Sizes and Types

Using casks to make single malt whisky

All single malt whisky is stored in warehouses, such as a dunnage warehouse, for a period of time. During this time, new make spirit is matured in oak vessels - commonly called “casks”.  This is so important to whisky that its often written into law; for example, American whiskey has to be matured in virgin oak casks, and scotch has to be matured in oak casks of specific kinds, like ex sherry.

But while certain aspects of cask maturation are written into the rule book, there is still a lot of variety.  This includes size, with casks broadly falling within the range of 200 to 650 litres.

Casks used to make Scotch

The three most common casks used in Scotch maturation reflect both legal requirements and availability of the casks.

barrel can hold approximately 190-220 litres of whisky (120-140 litres of pure alcohol); they’re sometimes called an American standard barrel, or a bourbon barrel.  Barrels are a by-product of bourbon production, as the American whiskey industry stipulates that virgin oak has been used.  While American distilleries can’t reuse these casks, the Scotch industry not only can, but very commonly does.

hogshead can hold approximately 225-250 litres of whisky (142-185 litres of pure alcohol).  Hogsheads are around 20-25% larger than a barrel.  They are often made from staves from bourbon barrels, reworked by coopers into this larger format.  It's not unusual for these casks to have held another liquid, like sherry, prior to being used in whisky maturation - and you may have come across the term ‘sherry hogshead’.

butt can hold approximately 475-500 litres of whisky (302-350 litres of pure alcohol).  That makes butts twice as large as a hogshead, and two and a half times the size of a barrel.  Sherry is often matured in butts, and in the same way that the scotch industry reuses barrels from the bourbon industry, so too do Scottish distilleries import butts from the sherry bodegas.

Clearly these different sizes of casks means differing amounts of whisky.  But the other important difference is in maturation times.  A smaller cask like a barrel means that there is a great ratio of wood to spirit - there’s more surface area for the liquid to interact with the wood.  This means the flavours mature more quickly, and a short maturation time is needed.  By contrast, a larger cask like a butt means a lower wood to spirit ration, and a longer, more gradual, maturation period.

Whisky cask sizes

While barrels, hogsheads, and butts are the three most common casks used in cask maturation, there are other cask types too - each with different capacities, different typical maturation periods, and in some cases different flavour profiles (for example sherry versus port). 

Type of whisky cask

Approximate number of litres

Approximate litres of pure alcohol

Typical flavour profiles

Maturation time (relative)
Bloodtub 30-35 21-25 Varied Finishing or very short

Octave or firkin

45-50

29-35

Varied

Finishing or very short
Kilderkin 90-100 60-70 Bourbon Short
Quarter cask 120-125 84-88 Sherry Short to medium

Barrel

190-200

120-140

Bourbon

Short to medium

Hogshead

225-250

142-175

Bourbon

Medium

Barrique

250-300

159-210

Wine

Medium

Puncheon

450-500

286-350

Sherry

Medium

Butt

475-500

302-350

Sherry

Medium to long

Port pipe

550-650

350-455

Port

Medium to long

Madeira drum

600-650

381-455

Madeira wine

Long
Tun 900-950 630-665 Varied Long

I hope this has been helpful! And if you have any questions, please do leave me a comment below - or email me. For further reading, you may enjoy our article on "how to make your own whiskey in five steps".

Slainte, Ed

Written by Ed Leigh

Ed co-founded TopWhiskiesTopWhiskies helps you find the best whisky from unique and independent brands. You've likely heard of us, because you're reading this right now. 

Leave a comment

All comments are moderated before being published