

Recently, I had the pleasure of presenting this topic at our monthly homebrew club meeting with the invitation extended from a fellow club member (thanks Doug!). I figured that it would make sense to sum up the presentation into a solid synopsis that would allow those interested to get off to a confident start. As a prelude to this conversation, we focused on barrel-aging clean beers, usually in regards to used (freshly emptied) spirit barrels. We will save the barrel aged sour talk for those with much more experience.

Generally speaking, the bigger the beer, the longer the aging timeline needed in order for the character to mellow and the beer to drink properly. Most styles we tend to think of commercial breweries pouring into empty spirit barrels are big, dark, rich imperial stouts, porters and barleywines, and for good reason. These styles benefit from a long aging process and readily accept the qualities that spirit barrels such as whiskey and rum have to offer. There is no saying that you cannot age a smaller, more delicate beverage in one of these vessels, but you may need to account for the flavor impact of both the wood and the spirit, along with the effects of oxidation from long-term storage of a less than air-tight barrel.

Character from Wood and Toast/Char

Doug and I had reviewed a few wood types in our discussion, however I believe there may be a few more to note. The two most common wood types for spirit and wine barrels are American and French; Hungarian, Slavonian and Canadian Oaks are also used but are less common, especially by way of homebrewer procurement methods. Barrels come in many sizes, and range from 5 gallons to 59/60 gallons for wine, with the most common sizes being 15, 30, and 55 gallons for spirits. American Oak is the most forward in flavor and is used for all spirits labeled as “bourbon” as one of the specific requirements for this spirit is aged for a length of time in a newly charred American Oak barrel. American Oak imparts a big vanilla and coconut sweetness due to the higher quantity of lactones and lignins in the wood compared to French. French Oak on the other hand, although still carries a nice vanilla sweetness, lends to a more spicy character, specifically in the realm of allspice and cinnamon. The major physical difference is that French Oak is tighter grained and less dense than American which allows it to impart more subtle, silkier tannins to the spirit, wine or beer. American Oak, being more dense, can be sawn instead of split which makes them abundantly cheaper than French Oak.

Charring is done to change the nature of the oak itself, which allows the spirit/wine and the oak to mingle and create deep rich flavor profiles. Hemicellulose, among other complex wood sugar/starchy chains, is a major contributor to flavor when charred. The process of charring will break down hemicellulose chains into smaller wood sugars, and the heat further caramelizes these sugars to give off the reminiscent toffee, brown sugar and caramel flavors and aromas. Lignin is also a key contributor of the spicy vanilla flavors and aromas; the more charred, the more these flavors develop. Lactones, as mentioned previously, impart the nice coconut flavors as well.

The most common char levels are #1-#4 ranging from directed contact with flame from 15-55 seconds respectively. This char, besides providing unique flavors, creates a thin layer of charcoal from the burnt wood, which acts as a filter that rids the contents of multiple off flavors apparent with young spirits and wines.

Barrel Care and Maintenance





Most of the time, if the barrel is newly made, of course depending on how long from its production to your acquisition, it can be quickly rinsed with hot water and filled with beer. If the barrel is freshly emptied (personal experience says 2-3 weeks), then the staves are mostly water tight and if it previously held a spirit, it can be filled directly. There are some techniques however, that can be used to ensure a clean aging process using either new or used barrels.

New barrel/Rehydration – using chlorine free hot water, fill the barrel to 20% of its volume, insert the bung and shake. Usually, depending on how long after the barrel was made, the staves should swell fairly quickly. Make sure to set the barrel on each of the heads for around 20-30 minutes to promote swelling of the stave ends and the head joints as well. Once confident that the barrel is water tight, try to fill the entire barrel and check for leaks.

If the barrel you have has set for quite some time, and does leak, rehydration is the next necessary step. Depending on the degree of space between the staves, and the size of the barrel, two different methods can be used. Using the method of new barrel preparation above, the staves can be swelled fairly easily, especially if the stave spaces are small and/or the barrel is large. If the barrel is small, and leaking considerably, fill a large container (Rubbermaid tub) with warm water and submerge the barrel in the full tub, rotating it periodically. Over the next few days the staves will swell and the barrel will become water tight.

Used Barrel Cleaning/Storing – Ideally, once the barrel has been emptied, a fresh batch should be racked in to avoid the necessity of cleaning and “holding” the barrel for storage. If this is not a possibility, a cleaning/holding solution can be made and used by combining 1oz of citric acid and 1.5oz potassium metabisulfite per gallon of barrel volume. This mixture inhibits further yeast and bacterial growth, thusly lowering the chances of spoiling your next beer in addition to keeping the staves swelled and in good condition.

Short Turnaround Time – This method stems from personal experience and a culmination of information found in the brewing forums regarding barrel aging homebrew. If you have purchased a used spirit barrel, and cannot fill the barrel immediately, its easy to keep it clean and swollen, while simultaneously preserving the spirit character by simply dumping a bottle/handle of mid-level spirit into the barrel and coating the inside of the staves and heads periodically by rolling the shaking. I have done this with a 15 gallon bourbon barrel and a handle of Jim Beam Bourbon for 4-5 weeks after receiving the barrel, which was also emptied 2 weeks prior, and had no trouble aging the beer for the next 2 months.

Pseudo Barrel-Aging

My personal favorite method used to impart an almost authentic barrel-aged character to a beer is by using oak cubes, chips or spirals soaked in a spirit of my choice. As with barrels, surface area (surface area-to-volume ratio) plays an important part in both the character being extracted from the wood and the length of contact time to impart the preferred level of character. Wood chips are thin and have a very large surface area compared to cubes and spirals, and spirals mores than cubes. Most evidence online suggests filling a jar with the wood of your choice and covering them with 8-16oz of spirit on brew day. This allows for plenty of time for sanitation of the wood by the spirit and flavor melding between the two components. Then, when the beer is ready for secondary bulk aging the wood can be added. I would suggest adding the entire contents, wood and spirit, to the beer to maximize the “barrel” character. I have decanted off of the wood in the past, adding the cubes only, and have noticed little to no spirit contribution to the beer, which was very disappointing. Rich, dark beers such as stouts and porter may benefit from the full 16oz of liquor, while styles such as barleywines and wheat wines may only need 8oz or less. The amount of cubes and chips may vary as well. The same suggestion pertaining to darker beers is appropriate here as well. Darker beers may benefit from a larger portion of oak. Cubes for example are usually sold in 3oz packages, which is middle of the road for what is discussed online, with even more evidence supporting poor character and over oaking with amounts in excess of 4oz.

Readying the Beer After Aging

There is a plethora of information regarding aging big beers online and in home brewing prints and periodicals for which many of those advocating for strict timelines on aging certain styles (i.e. wheat wines need a minimum of 3-6 months before consumption). The best advice has been “the beer is ready when you say it’s ready.” With wood and spirit aging, I would recommend weekly (or less frequent if you prefer) “quality control screenings” to see how the beer is progressing. This should not involve sampling enough of the beer to risk cutting a bunch of packaging volume with frequent hydrometer readings, but a 1oz sample or so using a small thief or bulb-syringe should be fine to adjust the aging process accordingly.

Cheers!