The Ultimate Guide to Barrel-Aged Beer

Barrel-aging beverages is common in the distilled spirits and wine world, but whiskey and wine lovers aren’t the only ones chasing the oak-barrel flavor these days. Craft brewers have rebirthed the process of aging beer in barrels to create new, complex flavors that have more than just a cult following.

TapRm has an extensive collection of barrel-aged beers, and our selection is ever-changing. Our craft brewers offer seasonal brews and release their aged beverages in smaller batches than large-scale brewers.

To understand the care and obsessive attention to detail that goes into barrel-aging beer, we’ll talk about what it is and the history of its use. We’ll also tell you everything you need to know about sampling a barrel-aged beer and give you some recommendations for barrel-aged beers you can try right now.

What Is Barrel-Aging?

Aging beer in barrels is historic, dating back to the 1800s, but not for the reasons you’d think. Before the advent of stainless steel, all liquids were stored and transported in wooden barrels. Wooden barrels (usually made of oak) were sturdy and could withstand transportation by ship better than other materials.

The wood barrels naturally lent their own flavors to the beer they carried. This wasn’t intentional but rather a side effect of the only reliable storage and shipping method available at the time. Usually, a delicate sweetness was the result of barrel storage and transport.

As beer-making progressed, the beer makers noticed that they could harness the power of the barrel and better control the effect of the wood on the beer by preparing the barrels before use. This was done in an effort to thwart the oak taste and sweetness the wood naturally diffused into the beer.

By soaking the barrels in water and scouring with hydrochloric acid, brewers were able to better dissipate the oak flavor and aroma. American brewers even began lining their barrels with pitch to prevent the wood from changing the flavor of their beer.

The Problems With the Barrels

Wood barrels of old were fraught with problems. Even though they were considered the safest and most secure way to transport beer, they frequently leaked and ruptured. Since it was porous, the wood also allowed natural oxidation to occur. Sometimes, if the beer arrived at its destination later than expected, it would be spoiled.

Porousness also allowed natural yeasts and bacteria to grow inside the barrels, further changing the beer and affecting fermentation. Long before sours were popular, oak barrels were creating them unbeknownst to the brewers. This resulted in beers that didn’t yield consistent flavor.

Once stainless steel casks were invented, brewers had absolute control over the consistency and flavor of their beer. It also meant they could better sterilize the beer and control the fermentation process. As such, barreling beer in wood casks became a dying practice, reserved for small operations or outlawed moonshine-type productions.

The Return to the Barrel

A wave of unearthing traditional beer-making methods has coincided with the craft beer movement. Experimental brewers use time-honored traditions as the basis for creating new beer and challenging the complexity of flavors available using these methods.

It’s no surprise, then, that craft brewers have become obsessed with barrel-aging. The variety of elements in the wood barrels themselves can create rich flavors and aromas simply not achievable by other means.

Why Barrel Beer?

The most common reason a brewer will barrel-age their beer is to allow the beer to absorb the flavors of the wood and the flavors of whatever liquid was previously distilled inside it. These compounds are extracted from the wood over time. Thus, the longer the beer spends inside the barrel, the more it will become infused with those flavors.

There’s also the issue of wild yeast and bacteria. Once considered ingredients that would spoil beer, craft brewers use these ingredients to create sours, beers that are specifically brewed and fermented with wild yeast and bacteria to develop a specific tart taste that is earthy, dank, and fruity.

What Kinds of Barrels Are Used?

When it comes to aging their beer to perfection, not just any barrel will do. Brewers are very particular about the kind of wood they use and the beverage that was curated in it prior to their use.

  • The wood. Most often, American white oak is the wood of choice. However, you’ll also see other varieties used, such as poplar, ash, acacia, cypress, redwood, pine, chestnut, and eucalyptus. Other woods offer different flavors but are generally less stable than oak.
  • Sourcing the barrels. By law, distilled whiskey and bourbon barrels can only be used once. This means that the whiskey and bourbon industry creates used barrels as a byproduct. While you might assume that this would make barrels readily available and inexpensive for brewers, the competition for leftover barrels is high.
  • American barrels are highly sought after by brewers worldwide, with the price per barrel sometimes reaching $200-$400. As such, barrels are usually sold to the highest bidder.

The distilled whiskey and bourbon industry isn’t the only place where barrels are sourced, but it’s arguably the most popular. Bourbon, especially, naturally lends a complementary flavor to beer. However, barrels that once housed wine, rum, and sherry are often used also.

What To Expect From Barrel-Aged Beer

Barrel-aging a beer changes its taste, mouthfeel, and fermentation. Heavy beers withstand barrel-aging quite well, although some lower-gravity beers are still barrel-aged for short periods of time (6-12 months) to infuse a bit of oaky flavor.

Several factors contribute to a barrel-aged beer’s unique flavor: the wood, the previous contents of the barrel, oxygenation, bacteria, and yeast.

The Wood

Although every type of wood will yield a slightly different flavor to the beer, it can be extremely difficult to differentiate unless you have a finely tuned, extremely discriminating palate. For our purposes, we’ll cover the variances you can expect from oak-barrelled beer.

  • Tannins. Tannins contained in the oak act as preservatives for the beer it holds. Tannins are antioxidants that help prevent over-oxidation, which could spoil the beer.
  • Lactones. Lactones are oak lipids that give off a woody aroma. Beers that have been barrel-aged will be infused with an oak-like scent due to the presence of lactones in the barrel.
  • Hemicelluloses and phenolic aldehydes. These are both oak polymers that, when heated, produce flavors that brewers look for in their resulting beers. Phenolic aldehyde produces vanillin, which infuses the beer with a vanilla or even coconut flavor.
    • Hemicellulose produces flavors of burnt sugar and caramel. When combined with certain yeasts, it produces earthy, rustic flavors like leather and smoke.

These natural aspects of oak help infuse the beer with a unique flavor that is virtually impossible to replicate outside of a barrel.

The Previous Contents of the Barrel

The barrels used for aging beer are nearly always recycled from a winery, distillery, or another facility. In other words, they’ve all previously held another liquid. The liquid previously contained in the barrel also contributes to the flavor and aroma of the beer that will be aged inside it.

Flavors vary depending on what was held in the barrel. For instance, bourbon will naturally infuse beer with sweet vanilla and coffee flavors that are robust and full.

Sometimes, barrels are charred before distilling bourbon and whiskey, giving the barrel a naturally smoky sweetness that will also infuse the beer.


Say the word “oxygen” in a brewery, and you’ll most likely be met with disgruntled faces. Oxygen spoils beer, and exposing beer to oxygen during any part of the beer-making process can render it sour and stale.

The caveat is barrel-aged beers. During barrel-aging, oxygenation is a prerequisite necessary for the beer to age properly. Slow, controlled oxidation cuts through hoppy bitterness, heightens maltiness, and results in sweeter, more pungent flavors.

Too much oxygen can still result in spoilage, leaving beer with an acidic flavor. Proper temperature control during the barreling process is necessary to prevent this from happening.

Bacteria and Yeast

What makes a sour beer a sour beer? Bacteria and yeast! By experimenting with different yeasts, including wild yeast like brettanomyces, craft brewers are able to create sour beers that yield the unique, dank flavors of a farmhouse or wild ale.

Likewise, bacteria naturally occurring inside the barrels contribute to the extended fermentation of the barrel-aged beer, altering the flavor in a manner consistent with the brewer’s intended design.

The Barrel-Aging Process

Barrel-aged beer is created in the same manner as other beers: malting, mashing, boiling, and fermenting. However, before the bottling process, the beer is then removed to wood barrels for aging.


Preparing the wood barrel for beer storage is different depending on the desired outcome of the beer. Some brewers rinse, scour, or clean the barrels before storing the beer. If a new barrel is being used, it is typically rinsed to ensure that any remaining wood chips or particles don’t wind up in the beer.


Crucial to the barrel-aging process is the temperature setting. The brewer will adjust the temperature to meet those expected outcomes depending on the desired result. Warmer temperatures, for example, result in woodier notes and stronger, bolder flavors.

Cooler temperatures work well for producing lower-gravity beers with mellow flavors and less hoppiness.


Unlike wine, you’ll rarely find a beer aged longer than five years. Typically, barrel-aged beer is aged anywhere between 12 months to 5 years, depending on the desired outcome. Darker, heavier beers, like stouts and malts, can handle lengthier times in the barrel.

Most Popular Barrel-Aged Beers

Not all beers are qualified for barrel-aging. Again, most beers are crafted to be enjoyed fresh. Some IPA’s, like juicy IPA’s and hazy IPAs, begin to degrade immediately after production. These usually require constant refrigeration.

For other beers, spending time in a barrel can yield a different flavor from their original, non-aged counterparts.


Dark, rich espresso in color, stouts are massive beers that age well in the barrel. Stouts were the first beers to be barrel-aged in the rebirth of the barrel-aging process. The grainy, thick texture of the stout naturally lends itself to a complimentary earthy flavor produced by the barrels.

Aging the stout allows the beer to pick up sweetness and flavor from the barrel, and the alcohol content of a heavy stout will naturally pick up more of the barrel’s flavor. The resulting stout is equally as bold as the original, but with a sweeter, warmer flavor and even smoother mouthfeel.

One to try: Founders Brewing Kentucky Bourbon Stout. This is a big imperial stout that will hit your palate with coffee and chocolate. The smooth, bourbon barrel-aged finish feels silky and full-bodied. Barrels are charred to produce a smokey, oak aroma and taste.


Sours are beers that are layered with surprising flavors not welcomed in other beers. Intense wood, earth, funk, and farmyard flavors (wet horse blanket is a popular descriptive) permeate these cult favorites.

Sours blossom into even more rustic and dank flavors when they are barrel-aged. Lambics, Flanders, gose, American wild ale, and Berliner Weisse are all different styles of sours you might commonly find barrel-aged.

One to try: Goose Island Madame Rose. Goose Island was the first American brewer to bring back the barrel, and Madam Rose is a beautifully aged Belgian style brown ale aged in wine barrels atop cherries. The addition of wild yeast delivers a complex beer that is both spice and woody.


These wild ales make use of bret yeast and are usually straw to amber in appearance. These beers usually have a mild haze and herbal flavor. Many saisons rely on European hops that can be exquisitely strong. Barrel-aging reduces the bitterness of the hops.

One to try: Oxbow Brewing Company Phosphorescence. Fermented in French oak barrels, this saison has a beautiful gold color and provides flavors like tropical fruit notes, white pepper, and, of course, oak. Much like a sauvignon blanc, this has a dry finish.


Classic blonde ales aren’t always aged in barrels, but when they are, the result is a sweet, mid-level blonde ale that features a richer, more complex profile than their non-barrel-aged counterparts.

One to try: Wicked Weed Marina. Arguably a hybrid beer, this beer combines the dry, balanced aspects of a blonde ale and the unexpected fruitiness of a sour. You’ll get notes of peach, apricot, and cracker.

There are other styles of beer that are barrel-aged. Some Belgians and barley wines are barrel-aged to perfection.

Barrel-Aged Brews at TapRm

At TapRm, we specialize in making the craft brewer 3,000 miles away from you as close as your local pub. Through the building of a better beer infrastructure, we bring you the up-and-coming beers you wouldn’t normally be able to try.

Our selection of barrel-aged beers is extensive and ever-evolving. Trust the TapRm team to guide you along your barrel-aged beer tasting journey.


Brewers Association Beer Style Guidelines | Brewers Association

Barrel Aging | UC San Diego Extension

Brettanomyces - an overview | ScienceDirect Topics

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