Dear reader, if you’re a cocktail aficionado, as I am, no doubt you are familiar with the recent trend of barrel-aging libations. I trust that you have taken it upon yourself to try your hand at this mystical art. If however, you have been remiss in this regard, then I hope you will find inspiration in the description to follow. And for you rookies in the cocktail game, this is your chance. Start your journey with a barrel, and you won’t be disappointed in where it takes you.
Barrels have been around since at least the 4th century BC, when the Celts are believed to have developed the wooden barrel through adaptation of ship-building techniques. Sturdy, water tight, and easy to transport, the barrel didn’t take long to spread across the ancient world. Soon, the Romans were buying wine from Gaul that was stored in barrels, believing the taste to be superior to that of wine stored in their own ceramic amphora vessels. In time, the barrel became king of containers— reigning supreme from the British isles to the Black Sea coast and beyond. Expedience was surely the main factor in barrel usage, but discerning drinkers no doubt appreciated the more refined and mellowed taste of wine stored in barrels.
But what magic occurred in those oaken vessels? What led winemakers and distillers to begin aging their products in barrels? Today, barrel aging is considered such a vital part of alcohol production that it is mandated by law in some cases. In the United States, bourbon must be aged for a full year in an oak barrel before it can be called bourbon. The same is true for various other whiskeys, as well as brandies and wine. The reason for such regulations is consistency— if a product carries a storied label, consumers expect a certain level of quality. And with barrel aging, so comes that quality.
To simplify a complicated topic, barrel aging serves three main functions: oxidation of ethanol; extraction of sugars; and, infusion of flavor compounds. First, when a liquid is stored in a barrel, it is sealed in with air. Variations in temperature and pressure cause convection mixing within the barrel, thus exposing all of the contents to both the oak and the internal air pockets. When exposed to air, portions of the alcohol (ethanol) are converted to acetaldehyde, which provides a nutty flavor. Some of the acetaldehyde is in turn oxidized into acetic acid, which adds depth of flavor.
In addition to reacting with air, the alcohol too reacts with the oak. During this process, hemicellulose in the oak reacts with acids in the alcohol, resulting in the extraction of sugars into the aging drink. The higher the acidity of the drink, the greater the extraction of sugars. As the alcohol takes on more sugars, the taste is softened, and harsher spirits begin to lose their bite.
Finally, liquid aging in a barrel will take on some of the physical compounds present in the wood. In the case of oak, this means vanillin and tannins. These compounds are infused into the liquid, thus imparting new flavors. Vanillin, somewhat obviously, also occurs naturally in vanilla, and it is for this reason that aged drinks can have flavors reminiscent of popular sweets. Taken in concert with the oak tannins, the drink gains complexity in flavor through this infusion, as well as greater structure.
Wine and spirit makers have been using the barrel aging process for centuries, but if a barrel can do wonders for those drinks, why not to something more complex? As far back as the late 19th century, drinkers have been consuming pre-mixed cocktails that were stored in barrels. The storage method was mostly a matter of expedience rather than art, but in fact, the consumers of these drinks were the first barrel-aged cocktail connoisseurs. Chief among the ready-made cocktail producers was the Gilbert F. Heublein & Bro company. By the early 20th century, the Heublein company turned their expedient storage methods into a selling point. In their advertisements, Heublein made note of the fact that their Club Cocktails were “aged in wood” and had superior flavor. Up until the 1960’s, Heublien extolled the virtues of aged cocktails in their advertising campaigns, and to great effect.
How, or why, pre-mixed cocktails went briefly out of fashion is unclear, but barrel-aged cocktails are back and can be found in virtually any major city with a cocktail culture. Tony Conigliaro of London’s 69 Colebrook Row, and Jeffrey Morgenthaler of Clyde Common in Portland, OR, are generally credited with starting the modern barrel-aged cocktail trend. For his part, Conigliaro began by aging his cocktails in glass, while Morgenthaler focused on the use of barrels. In both cases, the result was a smoother beverage, complex, and with an appreciable mellowness.
Of course, as with any good hobbyist, drinkers love experimentation. Half of the fun of a barrel-aged cocktail is doing it yourself. All one needs is a barrel, a recipe, and inspiration. For me, the inspiration was the Negroni— a classic aperitif of Campari, sweet vermouth, and gin. Around my house, Campari is a somewhat divisive liquor, and has been described, in a word, as bitter. Fair point, it is in fact bitter (of the lovely, tongue tinglingly sweet sort, in my opinion), but what’s to be done? To that question, Mr. Jeffrey Morgenthaler provided the answer. Barrel aging.
After a bit of research, I found a distillery in Sperryville, VA, not far from my home outside of Washington, D.C., that sold small charred American Oak barrels for the purpose of aging white whiskey. Copper Fox Distillery makes a lovely whiskey, but I was on a specific mission on the day of my visit, and was soon the proud owner of a two liter oak barrel, sans whiskey addition. A few days and a trip to the liquor store later, the barrel was filled with pre-mixed Negronis (thanks to Jeffrey Morgenthaler’s recipe), and set on my counter to age for the next six weeks.
The results of this home experimentation were, if I may say, sublime. A Negroni almost completely cleared of bitterness. We conducted a taste test, side-by-side with a normal Negroni, and not only did the aged version have a deeper red color, but it had a subtler flavor theretofore unbeknownst to my Campari-loving palate. And best of all, the success served as proof of concept, and opened up all sorts of interesting cocktail possibilities. Currently, my barrel is softening up a batch of White Manhattans.
There are, mostly among the old guard of the liquor world, those who say that barrel aging is merely a fad. Something new and seemingly hip that cannot fail but to fade into obscurity. A cocktail, they say, should be pure and free of gimmickry. There is some truth to the idea that barrel aging is a departure from cocktail purity. But then again, is that a bad thing? One can imagine the elite of Roman society decrying those who stored their wine in barrels rather than ceramic amphora. And we all know how that fad played out.
For more information on the science and art of barrel aging, I recommend the very informative blog posts and articles on Art of Drink, Star Chefs, and Diffords Guide. For Jeffrey Morgenthaler’s recipes, see his blog post onjeffreymorgenthaler.com, and for additional recipes see Food & Wine Magazine’s guide to barrel aging. To order your own barrel, check out Copper Fox Distillery, or one of several other manufacturers and resellers.