Small Barrel Aging 101

By Richard Thomas

Renewed interest in small barrel aging has come up hand-in-hand with the micro-distilling boom, causing even big distilleries to get in on the act. Proponents of small barrel aging claim the use of smaller barrels allows them to create a superior product in a short space of time, an attractive proposition for a small start-up who would otherwise need to wait at least a few years before they could even begin to sell any product.

Yet critics claim small barrel aging accelerates only some of the benefits of oak barrel maturation, so the whiskey produced is left somewhat lacking. Even many whiskey-lovers do not really understand what happens inside an oak barrel over the months and years of primary and secondary maturation (or “finishing,” as the latter is often called), and therefore wonder what the advantages and disadvantages of using a 53-gallon barrel vs a 5- or 10-gallon barrel really are.

It’s All About Surface Area
Aging in a smaller barrel increases the proportion of interior barrel surface area to stored volume, putting more wood surface into contact with the whiskey within. It is a proven and demonstrable fact that this increased contact accelerates the rate at which the whiskey absorbs characteristics from the wood, such as color and an aged whiskey’s oaky and vanilla notes.

According to the American Distilling Institute, using a small barrel can turn out “an excellent product in only three to six months.” With such a quick turnaround time, it’s obvious why a new distillery might start with small barrel products, since it allows them to put something on the market in as little as half a year. The speedy maturation of small barrel aging is also a big plus for experiments, since it allows a distiller who is trying something new to see what the results might be much sooner.

What is true for micro-distillers and modern whiskey pioneers is doubly true of home distillers, for whom small barrel aging is usually the only practical choice. Few home distillers produce in the sheer quantity necessary to merit even one or two 53-gallon barrels, or have the patience necessary to wait many years to have a drinkable homemade whiskey.

The Downside
The key problem with small barrel aging is that it accelerates the absorption of everything else from the wood as well. A common misconception is that the longer a whiskey stays in the barrel, the better it gets. Nothing could be further from the truth.

Aging in oak is a delicate three-way dance between the climate, the whiskey and the wood. While the exact line is hard to determine with any specificity, aging a whiskey for too long imparts a nauseating astringency, especially if the wood in question is new oak.

This effect places a time limit on how long whiskey can sit in a barrel without “going bad,” and that limit comes much sooner for small barrels than big barrels. One or two years seems to be the most a whiskey can profit from being in a small barrel, and therein lies the problem. Many whiskey qualities come from esterification, or the reactions between wood acids, alcohol, oxygen, and various other chemicals, and those reactions take time. If you bottle your whiskey after 15 months, very little of that has happened, so critics of small barrel aging aren’t wrong when they say the processing choice “leaves something out.”

The decades-long aging periods that are a fixture of scotch-making produce such fine results in part because scotch-makers rely almost entirely on used bourbon, sherry and port casks for their primary maturation. Some of the oak’s less desirable qualities have already been used up during the first round of aging.

All bets are off for a small barrel finishing, as is the case for Laphroaig Quarter Cask. Finishing a whiskey in a second set of barrels is always meant to be a short term thing by its very nature, rarely lasting more than a year. For secondary aging, it’s hard to see what drawbacks small barrel use might have, if any.

Open Minds
Small barrel aging might not produce “traditional” whiskey, but what is traditional whiskey anyway? Even the products of a big, well-established label like Jack Daniel’s have changed periodically in ways that some found objectionable. Many whiskeys made today are quite different from what was being made a century or more ago, even for the big old names in scotch, Canadian and Irish whiskey that have been in continuous operation all that time.

Furthermore, more goes into an enjoyable bottle of whiskey that the oak its aged in. The size and nature of the barrel is just one factor, and while I can’t deny that small barrel aging leads directly to a more circumspect maturation period, that doesn’t mean it’s bad. Some whiskeys clearly come out very well indeed after only several months in a small barrel, in much the same way that some come out very poorly after several years in a big barrel.

The important thing to keep in mind about small barrel aging is that what matters is what you want from your whiskey. The proliferation of small barrel whiskey is a good thing in my book, because it means an experimentation boom in whiskey-making, and it’s great that American whiskey laws and organizations are liberal enough to permit such things. No one is telling Ranger Creek they can’t make mesquite-tinged bourbon in small barrels in the same way the Scotch Whisky Association (SWA) told Compass Box they couldn’t make The Spice Tree with French Oak staves. Think about that the next time a whiskey-snob scoffs at small barrel aging on the basis of “tradition.”