• Scrap-metal bird courtesy Dr. Evermor of the Forevertron

In February the celebrated Allagash Brewing Company of Portland, Maine, released FV 13, their first beer aged and soured in a huge oak vessel called a foudre. “FV 13” stands for fermentation vessel 13, the name the brewery gave to the foudre involved—they’d superstitiously skipped 13 when numbering their stainless steel fermenters, then doubled back to it for this wooden one, which formerly belonged to a winemaker. Allagash also ages beers in used wine barrels, but different kinds of business go on in a giant foudre than in a 31-gallon barrel. Fermentation vessel 13 holds 2,700 gallons, the same as a 14-foot inflatable ring pool—except that you don’t have to strain out leaves, hair, dead bugs, and band-aids after you age something in a foudre.

FV 13 is a sour, but it’s not a lambic. That is, its primary fermentation takes place under controlled circumstances, using Allagash’s house yeast in a closed stainless vessel. In traditional lambic making, fermentation begins in a koelschip—a large steel tray used to cool wort and allow wild yeasts and bacteria to float into it through open windows. Allagash built the first commercial koelschip in the States in 2007 (it may still be the only one, for all I know), and the fixture gave its name to the brewery’s scarce but much-loved Coolship series of beers.