Aging in oak barrels is no longer reserved for professionals… And yes, we’re entering into our stocks a mini chai of 4 to 25L barrels ! 😁
Welcome to the fascinating world of aging beer in oak barrels.
This ultimate guide will take you on a journey through the nuances of this age-old practice. Perfected over time by major breweries such as Cantillon, 3 Fonteinen and Jester King, wooden barrel aging is now opening up to home brewers.
What’s the difference between barrels and casks ?
It lies mainly in their size and place of origin.
Barrels and casks are relatively interchangeable. They are generic terms that do not specify capacity.
Barrique” is a much more precise term. It’s a “fût” (barrel) used by Bordeaux wineries, with a capacity of 225 liters and a height of 93cm. The circumference must be 1.84m at the “head/end” and 2.17m at the “bouge” (swollen part).
What’s the name of a barrel tap ?
While we’re on the subject of appellations, the oak barrel tap has a very specific name: the “Chantepleure”.
This information isn’t crucial, but you’ve got to admit it’s a funny name 😝
Why are the barrels made of oak ?
Before oak, it was common practice to use chestnut wood for transporting and storing wine.
The problem: this type of wood confers astringency and extremely powerful tannins.
Oak became the wood of choice for barrels because of its unique properties.
It is hard enough to withstand the pressure of the liquid and porous enough to allow good internal synergy.
It also imparts distinctive flavors and aromas, including notes of vanilla, coconut, roast and spice.
How to use an oak barrel ?
This proverb by Paul Morand, which can be seen everywhere at Brasserie Cantillon, perfectly represents the experience of aging in oak barrels.
Above all, it’s a story of patience…
The skills of a cellar master are not acquired overnight. However, the art of aging beer is not an insurmountable challenge.
If you’re tempted by the idea of aging a fine farmhouse brew, here are a few tips and tricks to get you started.
Seal and clean the oak barrel
When you receive your keg, it’s very important to reconnect it. Don’t worry, it’s not difficult.
- Insert the “chantepleure” into the hole provided and make sure it’s secure.
- Fill the wooden barrel by half with boiling water mixed with salt (15/20g per liter).
- Close the barrel and stir well to moisten the entire inner surface.
- Leave to stand for at least two days, stirring twice a day.
- Empty the barrel, rinse thoroughly and leave to dry.
- Fill with heated white wine and keep it full for 10 days (you’ll need to check and top up occasionally, as the wood can absorb up to 10% of the liquid).
- Finally, empty the barrel without rinsing and leave to dry.
Now you can age the beverage of your choice in your magnificent oak barrel !
If, after aging, you’d like to clean your wooden barrel, you can :
- Fill with boiling water
- Stir
- Empty
- Repeat 4 to 5 times.
We don’t currently sell any, but if you have a sachet of sulfur to mix with your water, that’s even better.
What’s the angels’ share ?
The “angels’ share” is a term used to describe the amount of liquid that evaporates during the barrel-aging process. During the first filling, it can be as high as 10% (c.f. step 6). Thereafter, it should be limited to 2%.
In any case, always keep a 10% headroom in your oak barrel. If there’s a change in temperature, the wood can return the beer it contains, thus increasing the volume.
Where to store your oak barrel ?
Whether full or empty, store your wooden barrel in a room with :
- Good hygrometry (75% to 80% – i.e. a fairly humid room)
- Few drafts
- Little light
- A stable temperature
- A cloth to cover the barrel and avoid UV rays.
How to store an empty oak barrel ?
If you are not going to use the oak barrel for several weeks, wrap it in plastic film and store it in the same conditions as above.
How to fill an oak barrel ?
You’ll see some people filling the keg with a funnel. Not a good idea…
Wood is a porous material, and oxygen is part of the aging process. However, this is no reason to maximize its intake.
The best thing to do is to proceed in the same way as with a resugaring bucket transfer.
Place your fermenter high up, connect a 9×13 silicone tube to the tap and fill the oak barrel from the bottom.
Bonus : if you’re equipped, you can even perform a CO2 purge before and after filling.
How long should you age your beer ?
An answer nobody likes : it depends…
Many parameters come into play. Age of wood, type of beer, storage conditions, etc.
Some people recommend :
- 1 month for beers below 6%.
- 3 months for stronger beers
But it’s a bit random.
New kegs will give a lot of flavor very quickly, whereas “old” kegs will take longer to develop their subtle, delicate flavors. The older the cask, the longer you can leave your beer.
Size matters…
The smaller the barrel, the greater the surface area of liquid in contact with the wood. The beer’s woody, tannic flavours will be all the more pronounced.
The trick is to find the right balance.
In conclusion, there really are no rules. Wood is a living material. Results are hard to predict. And that’s the spice of the art of ageing. It’s all about feeling. You’ll be the judge, and there’s only one way to do it…
Regular tasting
Taste, taste, taste.
Your palate will be your guide. Take notes :
- What happens on the nose ?
- What are the flavors on the palate ?
- What is the body of the beer ?
- Presence of astringency ?
- etc.
And if the woody flavours are too overpowering, there’s no going back !
Don’t panic ! Think blending…
This is a practice used by many barrel-aged breweries. If a barrel-aged beer is too strong or astringent, blend it with the same type of unaged beer. Experiment on a small scale to find the right balance. The final blend will be magnificently complex.
What type of beer should be aged in oak barrels ?
The choice is quite vast, and once again, there are no real rules…
Well, there are 2 prerequisites :
- The beer must not be carbonated
- Fermentation must be complete (you can leave your beer to ferment for a month before aging it in barrels).
Here are a few examples of beers that are ideal for barrel aging.
Dark and/or strong beers are excellent candidates :
- Imperial Stout
- Quadrupel
- Barley Wine
Farmhouse beers are also perfect for wood :
- Saison
- 100% Brett beers
- Spontaneous fermentation
Finally, you can try your hand at the famous English cask ales !
Ideal use of the oak barrel depending on its size :
From 4L to 6L :
For this cask size, we recommend “Blend”. As mentioned above, the contact between the liquid and the wood is maximized on small kegs. Woody/tannic/vanilla flavors will therefore quickly leave their mark on the beer.
An example :
On a 20-liter brew, you can age 3 to 4 liters in the barrel, leaving the larger part in the fermenter to rest quietly.
Once you’ve judged the aging process to be complete, collect the two volumes of beer.
You don’t have to follow this example. Remember, your palate is your guide, so test different ratios and find the one that suits you best.
Warning
The 4 and 6L kegs are not heat-treated. Before putting your beer in them, we recommend aging inexpensive whisky or wine to bring out more complex flavors.
Check it out :
10L and 25L :
These oak casks undergo medium toasting during production. This means that they will bring beautiful woody vanilla flavors to the beer, along with hints of coconut, chili and a hint of roasted smoke.
You can use them to age an entire brew, or to blend your own. Their size is ideal for home brewing.
Check it out :
Bonus tips :
Remember to write the bottling date on your barrel. This will help you keep track of your tastings ;).
If you plan to let the beer age longer than 6 months, use bottling yeast to kick-start refermentation when you bottle.
Age inexpensive bourbon for several months in your barrel. This will not be for drinking, but for marking the wood with its distinct flavors. Empty your keg, but don’t rinse it – age your beer directly in it.
Imagine your own Bourbon Barrel Aged Imperial Stout 😉
