A few years ago, a well-known international whiskey publication hired me to write an article about rapid-maturation technologies—and, for the first time in my writing “career,” I felt dirty. I wasn’t particularly keen to write the article, but the money was good, and articles in that particular publication held weight in certain circles. So, I sauntered forth, just trying to get the damn thing over with.
My day job is making whiskey in a fairly traditional fashion. The people for whom I work—whether in my own distilleries or my clients’ operations—always seem to expect a certain level of old-fashioned technique in my approaches. So, over the years, I’ve become a traditionalist. For my money, when maturing whiskey, nothing outdoes the marriage of Mother Nature and Father Time.
Yet while interviewing people and writing that article a few years ago, a funny thing happened: I became a bit agnostic to the whole concept of rapid maturation. Don’t get me wrong: For my own projects, I still think “rapid maturation” is an oxymoron. But I’ve learned that there are more nuances surrounding the arguments for these methods than I had previously considered.
So, here we are again. It’s 2025, and I’m writing on the topic once more—but this time, I believe, I can approach it with a keener edge.
[PAYWALL]
A Mature View on Maturation
Depending on how you define it, rapid maturation can include a wide array of techniques and technologies. At a glance, you could include the use of small casks, barrel alternatives such as oak chips and cubes, and the use of highfalutin, newfangled machines that run the spirit through various changes in pressure and temperature.
The interesting thing is that none of the technologies or concepts that follow are exactly “new.” Matured spirits have always been a source of financial frustration for distillers looking to bring in cash quickly. Liquids such as whiskey and brandy are a long-term play, to put it mildly, and anyone hoping to get rich quick would be better served investing their coin and energy in, say, flipping collectible Beanie Babies.
People have tried time and again to find ways to circumvent the vagaries of time and cask chemistry. We saw a lot of this occur during the initial years after Prohibition, when distillers were desperate to speed their casks along to some kind of financial return after their facilities lay dormant for 13 comically stupid years. And we continue to see it today, with varying levels of success.
With all that in mind, let’s take a more thoughtful look at some of the different methods employed in rapid maturation, their merits, their drawbacks, and—perhaps most importantly—where we can go from here.
Baby Barrels
Let’s start with the OG of rapid maturation: smaller casks.
In the modern distilling industry, the standard barrel size is 53 U.S. gallons, or about 200 liters. In the United States, we simply refer to these as the “standard” whiskey-barrel size, while the rest of the world often calls them ASBs, for American standard barrels.
Given their ubiquity and cultural pervasiveness, you’d be forgiven for assuming that the ASB has always been the preferred size for most matured spirits, especially whiskey. However, that 53-gallon size is a relatively recent phenomenon in whiskey history. Before World War II, the standard for whiskey barrels was 48 gallons (182 liters). Before the 20th century, 35 to 42 gallons (135 to 159 liters) was the norm. Before that? It wasn’t uncommon to see many distillers use sizes as small as five gallons (19 liters), sometimes referred to as “blood tubs.”
In the early to mid-2000s, many fledgling craft distillers started a steady move toward the use of smaller casks. Depending on who you asked, the idea was to increase the surface-to-volume ratio inside the barrel. For comparison, the inside of a 53-gallon barrel has a ratio of about 198 square inches per gallon; for a five-gallon barrel, that jumps to 276 square inches per gallon.
You can see the attraction here. More wood surface is exposed to a smaller amount of liquid, so you get greater wood extraction into the spirit in a shorter amount of time. Boom! You’ve got yourself a matured spirit ready for sale in a fraction of the time. If you view four years as an optimal maturation time in an ASB—and yes, it depends on a million other factors—then it’s possible to mature spirit in a five-gallon blood tub in as little as four months, sometimes even less. And many distillers do just that and have been somewhat successful with it.
But don’t go calling the cooper just yet—there are some notable drawbacks to this approach. Smaller barrels cost a lot per unit volume. They also take up more space per gallon of maturing stock. “But,” you might say, “I’ll be maturing spirit faster and bringing in mucho dinero, so the price and space trade-offs are worth it.” Maybe. However, there is an enormous elephant in the room, and its name is cask chemistry.
If your definition of a mature spirit is one that’s obtained a maximum level of barrel extractives, then small barrels will totally work. But—and this is epic-sized but—many of the other important chemical reactions that make a mature spirit delicious don’t move at the same pace. We’re talking about esterification, oxidation, and the reduction of unwanted new-make spirit character.
Now, I’m a distiller who says you can’t make good spirit using small barrels. I’ve worked for award-winning distilleries that have done it, and I know many other folks who consistently do it at a high level. What I will say is that making high-caliber spirits in small casks is generally more difficult than using larger barrels. Your distillation cuts have to be tighter. Your fermentations have to be cooler and more controlled. A low-congener-producing yeast can help… and the list goes on.
Not-Barrels
But what about other wood formats, besides the barrel? There are a ton of options in this department.
The most common products you’ll come across are wood chips and wood cubes, which work under the same principle as smaller barrels: They can increase the amount of surface area available for extraction of wood compounds into the spirit. A wonderful thing about these products is that if you spend a little time searching, you can easily find chips or cubes made from woods outside the usual suspects of American or French oak.
In recent years, there’s been an increase in the use of whole staves and stave inserts. Most famously, perhaps, Maker’s Mark uses the addition of French oak staves to produce Maker’s Mark 46. In this case, the distillers insert 10 staves into the primary maturation barrel once the bourbon has reached a predetermined maturation profile. They then place the newly staved barrel back into the maturation cellar so the staves can do their work.
Other barrel alternatives include the “honeycomb” wooden inserts produced by Black Swan Cooperage in Park Rapids, Minnesota. These inserts are smaller than staves but have a vastly increased surface area compared to traditional staves. Black Swan also produces the “Squarrel,” which, as the name implies, is meant to behave as a square barrel—it’s essentially a metal cage that lets you place various stave inserts inside. And, because the shape is square, they stack easily, making space considerations a breeze.
When it comes to these other formats, there’s an immense amount of flexibility and creative freedom. You could choose to mix and match all manner of different stave types to create your own bespoke “barrel” environment. It’s easy to see why so many of the pros go along with these alternatives—they offer a wild amount of creative flex compared to your standard barrel system.
However, here is where I’ll drop the other shoe: In my experience, most of these alternatives work best when used in conjunction with a cask, and not as the sole maturation driver. For instance, Copper Fox Distillery in Virginia makes its single-malt in standard barrels, but it also adds small amounts of applewood and oak chips.
Can you use chips, staves, and cubes to speed extraction along? Absolutely. However, much like the use of smaller casks for the same goal, the resulting liquid is often skewed heavily toward wood without removing enough of the brash new-make spirit character. Basically, the maturation process is a little one-sided, favoring the extraction of wood compounds, but little else in the way of actual maturation reactions ever catches up.
But that leads us to the next topic of discussion on our rapid-maturation journey: the use of maturation “reactors.”
Reaction Time
At some point in the past decade or so, it’s likely that you’ve stumbled across an article in your daily doomscroll that discusses how a distillery has discovered a way to circumvent maturation chemistry’s onerous temporal dictums, so now they can “age” a spirit in months, weeks, or even days. There are now a number of companies out there playing in this space to varying degrees of success.
Tom Lix of Cleveland Whiskey is one of the more front-facing mavericks of this new generation of tinkering distillers. He produces his Underground Bourbon Series by “controlling for temperature changes, pressure, oxygen infusion, and finally cavitation.” It’s a proprietary process about which he is cheekily tight-lipped, but we do know it lets him take a youthful bourbon and layer it with more mature characters. Perhaps the most interesting bit about Lix’s approach is that he can finish his whiskeys with a variety of different woods that rarely, if ever find, their way into the world of whiskey—or any other spirits for that matter. Current offerings include whiskeys finished with black-cherry wood, applewood, and sugar maple.
Bespoken Spirits began as a disruptive whiskey startup led by former Silicon Valley execs. In recent years they’ve located themselves in the lion’s den of American whiskey production—Lexington, Kentucky. Similar to Cleveland Whiskey, Bespoken is mum on exactly how their processes work, but they appear to have a like-minded approach. They take previously barreled whiskey and finish it with various woods cut into “niblets,” which can be added to the whiskey inside a vat. While that sounds simple on paper, from personal conversations I’ve had with folks at Bespoken, I suspect there is a lot more gadgetry under the hood than their press releases let on.
Probably the most prominent distiller of the rapid-maturation movement has been Bryan Davis of Lost Spirits in Las Vegas. (Sadly, Lost Spirits closed its doors in April 2024.) In the early 2010s, Davis began experimenting with putting his spirits into contact with wood and raising the temperature to somewhere between 140 and 170°F (60 and 77°C). He would then monitor for the increase in a marker ester, ethyl decanoate. Once the level of ethyl decanoate had reached 1.5 to 1.7 times the original concentration, he deemed the spirit “matured.”
The Terressentia Corporation—now apparently defunct—made waves many years ago with their own take on rapid maturation. There isn’t a whole lot of specific info on exactly how their process worked—more proprietary tech—but the company made note of using “ultrasonic” technology. Basically, they agitated the spirits in some way, in the presence of oak, to speed things along. In some ways, that wouldn’t have been too different from the handful of distillers who blast music at their barrels—the theory is that the vibrations cause a faster extraction of oak compounds.
The thing is, these technologies aren’t really new—many companies have tried this stuff before.
Progress, in Perspective
After Prohibition, people filed a wave of patents at the U.S. Patent and Trademark Office addressing the problem of spirit maturation time. (Here are a few worthy of your search engine’s time: United States Patent No. 2017235, 1935; United States Patent No. 1990266, and United States Patent No. 2180685.)
Many of the technologies proposed back then would have operated along similar lines—you might heat the spirit in the presence of wood, and there may or may not have been some agitation involved. Sound familiar?
So, why didn’t any of these technologies ever take off? Why aren’t more distillers using the more modern iterations of these rapid-maturation reactors? For some, including myself, it simply comes down to a stubborn adherence to tradition. In my case, as I said at the beginning, I make very traditional styles of whiskey. Newfangled gadgetry has no place in our brands—it just wouldn’t make sense.
However, I think there’s more to it than that.
For a great set of discussions on why rapid-maturation technologies haven’t been more widely adopted, I suggest it’s well worth your time to read my friend and colleague Gary Spedding’s articles on the subject that he wrote in recent years for the American Distilling Institute.
The long and short of it is this: Spirit maturation is chemically complicated. As Spedding writes in the more recent of the two pieces, when it comes to spirit maturing in wood and all the chemistry associated with it, there are an incredible number of people and hands involved.
Think about it: You have the forester picking out which trees to harvest from where. Then there are the coopers and the differences among their manufacturing techniques and heat treatments. We then arrive at the distiller, who complicates things immensely because virtually no two distillers produce the same distillate—and that’s not even going down the rabbit hole of different starting materials, such as grapes, grain, cane, etc. When it comes to studying maturation, then, the sheer number of academic disciplines involved is mind-boggling. (Spedding names a few of those: forestry, engineering, microbiology, physics, biochemistry, among others.)
That brings us back to the question of why these rapid-maturation technologies haven’t taken off yet. In my opinion, none of them currently produce a spirit at the same level of quality that can be made using traditional maturation methods.
Now, don’t get me wrong: Some of the technologies do come close. I’ve tasted examples of Bryan Davis’s work and have often walked away quite impressed. Still, I have to concede that even those moments are fleeting and that the spirit never quite hits the high bar that more traditional examples have set. And, if you consider everything involved in the study of maturation, you can see why perhaps these technologies haven’t hit the mark yet. The science is complicated as hell, and it just hasn’t gotten there yet.
But don’t write these maturation reactors off just yet. In my mind, they do have some incredibly valuable uses. When I was researching this topic years ago, my mind was unexpectedly changed on the subject in a way that I couldn’t have anticipated. I realized that these technologies can be quite useful to approximate the results of more traditional maturation methods while shortening product-development cycles.
Let’s face it: Maturation takes a long time, and if your company wants to develop a new product using a new type of cask or to see how a new distillate might behave in the barrel, then some of these methods could be quite valuable to you. With rapid-maturation technologies, you could drastically shorten product-development cycles by simply seeing whether your ideas have any legs. Sure, the end result of these experiments likely won’t be perfect, but it should be able to tell you whether a particular idea is worth pursuing in a traditional maturation cycle.
The barrel itself is old technology, used for the movement and storage of food and drink for centuries, if not millennia. When it comes to spirit maturation—and despite our best efforts and all the science afforded to us over the past 150 years—we have yet to really find a way to improve upon the simple combination of spirit, wood, and time.
For me, that’s okay. Some things, like great spirits, are worth the wait.
