We know D.C. Get our free newsletter to stay in the know.

At its worst, attending a food or drink “tasting” means borrowing a nice jacket, thinking about my pinky placement, and committing that heinous act of criminal waste: the swish-and-spit. It begs a level of restraint that I have a hard time keeping in front of exciting beer. I’m getting better -–- I now slow my drinking when my notes devolve into emoticons –— but it’s easier to stop and smell the roses with the help of an instructor.

There are few better instructors than Garrett Oliver (pictured), Brooklyn Brewery brewmaster and cultural ambassador to a nation of enthusiastic guzzlers. He led a tasting, “The Art of Barrel-Aging Beer,” at the National Geographic Society last week, with eight beers that have enjoyed woody hibernation. (See the Drool List below.)

Oak barrels were the original beer vessel, the wood being dense enough to hold liquid but pliable enough to be bent into slats. Today’s stainless steel kegs are nonreactive, but early brewers scorched their wood with boiling water and even hydrochloric acid to get their barrels flavor-neutral. (Though as Radioactive Man can tell you, such a strong acid will leave a mark on barrels as well as protective goggles.)

Now craft brewers are finding the good in wood. Because it’s porous, wood allows for very slow oxidation, which can make darker, malty beers more complex. Wood can also host microflora, bacteria that add the sourness to wild ales and lambics.

Oliver described the importance of a barrel’s “former resident” –— the wine or whiskey or whatever that first made its home there. As a tenant, bourbon leaves the place smelling like vanilla, as does Cabernet sauvignon, though to a lesser extent. Scotch casks become smokehouses. Port, sherry, and Asian liquors like shochu (sometimes aged in bamboo) also leave their spirits behind; some sherry casks have yeasts that will feast on a beer’s sugar, burping out phenols of exotic flavors.

The night’s beer lineup ranged from tart sour ales to big, bourbon-y stouts, but my favorite was the Harviestoun Ola Dubh 30, a Scottish old ale rested in Highland Park 30-year-old casks. After a parade of sugar and spice from the Belgian-style ales, the Ola Dubh was like sinking into a fat, buttered slice of pumpernickel. Its peaty character enveloped the table in, as Oliver said, “an aroma that reminds you of a childhood you never had.” Its smooth, chewy maltiness had the depth of a charcuterie house. This is a beer to get lost in.

Thirsty for vicarious drinking? Here’s the Drool List from the Art of Barrel-Aging Beer:

  1. Hitachino XH (Kiuchi Brewery, Japan)
  2. ‘t Smisje Calva Reserve (Brewery De Regenboog, Belgium)
  3. Russian River Consecration (Russian River Brewing, Calif.)
  4. Abbaye de St. Bon Chien 2007 (Brasserie des Franches-Montagnes, Switzerland)
  5. Ola Dubh 30-Year (Harviestoun Brewery, Scotland)
  6. Brooklyn Black Ops (Brooklyn Brewery, N.Y.)
  7. J.W. Lees Harvest Ale (Port Cask) (J.W. Lees, England)
  8. Goose Island Bourbon County Stout (Goose Island, Chicago)

Photo by Zak A