I saw this on Twitter the other day and it blew my mind:
After immediately falling down a Google hole about it, I discovered that this is, indeed, true! A butt, also known as a pipe, is a unit of measure for English Brewery Cask Units and English Wine Cask Units. It's the second-largest barrel size, equal to half a tun, which was typically 252 Imperial Gallons (although that exact quantity has changed throughout history; current standards place an English Tun at 259 US gallons or 216 Imperial Gallons).
According to Difford's Guide, the British brewing industry continues to use a Butt metric equal to 108 imperial gallons; this is, apparently, different than a Sherry Butt, which is more long and slender than other barrels, and holds between 105 and 110 imperial gallons.
A 2014 Gizmodo article was similarly mind-blown at this discovery, and did a little research into the etymology (buttymology?):
The words are not only derived from Old English but also Dutch, Italian, and French. Butt actually comes from "botte," a Medieval French and Italian word for boot. In Italy, at least, botte is still used to refer to a wine cask.
This makes me even more confused about Pork Butt, which is in fact a shoulder, but named for a boot that's also a barre (and can also mean "punches?"). Etymology Online offered some further clarity, connecting this all back to the Latin "buttis," a word used to refer to a cask, and which later became adapted into "bottle."
Anyway I just spent a buttload of time researching butt barrels.
Casks — barrel, butt, punchon, pipe, barrique, hogshead [Simon Difford / Difford's Guide]
A Buttload is an Actual Unit of Measurement [Commonplace Fun Facts]
Casks (barrels, hogsheads, butts) [Whiskey Invest Direct]
'Butt' is an actual unit of measurement [Adam Clark Estes / Gizmodo]
Image: Public Domain via NeedPix
