Barrels, Foeders, Wood Fermentation & Aging.

BY CHRIS MEADOWS, BREWMASTER @ ELKMONT EXCHANGE,

KNOXVILLE TN

Why ferment/age on wood?

In modern day, the intention of fermenting/aging beer on wood is

to impact the character and flavor of the beer in a desired

manner.

This process should yield a more complex and unique product

than before its transformation.

Why ferment/age on wood?

What type of influences are we talking about?

- original/natural

- toast, char (ranging from light to heavy)

- secondary characteristics like wine, ports, or spirits

Wine has a softer profile, which allows yeast or grains to shine, while

spirits like bourbon may be overpowering and a dominant contributor.

Why ferment/age on wood?

Oak is full of many flavorful and aromatic compounds and chemicals

that, when added to beer, create another level of depth and

complexity.

Why ferment/age on wood?

- Some styles of beer are better suited for aging vs others

- Not all wood aged beers are high gravity

- Some people view wood as the fifth major ingredient in beer making

- Wood presents an ideal breeding ground for wild yeast and bacteria

Why ferment/age on wood?

Set intention. If you’re going for a clean beer with no additional

fermentation, the barrels may need to be steamed for sanitation purposes.

If you’re going for a wild or sour beer, wild yeasts and/or bacteria may

need to be selected for a secondary fermentation to begin.

Why ferment/age on wood?

- Brewers favor oak as the primary wood used for producing barrels for its:

- Strength

- Resistance to decay

- Water tight, yet slightly porous to air

- Relatively high level of tannins

The right amount of tannins can add bitterness and mouthfeel. Too much

can be harsh. Oak isn’t necessarily the best in every situation, but in terms of availability and consistent quality, it’s a winner.

Why ferment/age on wood?

A few examples are:

- Furfural, which lends caramel sweetness

- Eugenol, which is clove-like

- Vanillin, the most recognizable flavor, tastes and smells like vanilla

- Lipids, which constitute the oils, fats and waxes found in the wood, are

responsible for oak lactones, which lend coconut and aromatic wood

flavors.

These are the basic flavors found in all types of oak, and the ones we as

brewers are looking for.

Ways to age

There are many ways to age your beer including the use of barrels,

puncheons, foeders, chips, spirals and staves.

This is often referred to as cooperage

Barrels & Puncheons

A barrel, cask or tun is a water tight hollow container made of staves

bound by wooden or metal hoops

Barrels & Puncheons

Barrels & Puncheons

Barrels & Puncheons

Barrels & Puncheons

Foeders

A foeder is a Dutch word referring to a large wooden barrel set on

end used for either long term fermentation or primary fermentation and

inoculations. Sometimes spelled foudre, foedre

A foeder can range in size from home brewer to commercial scale. Foeders

allow a slow ingress of oxygen into the beer that is easily supervised with the

tasting valve.

Foeders

The high beer to wood ratio allows the beer to mature and

develop whereas smaller barrels may progress sooner which may

lead to over-acidification before the beer is fully developed.

Foeders

Foeders also allow for greater capacity compared to the footprint

barrels take up.

Because the beer is coming from one vessel, you will have a more

consistent and reproducible product.

Foeders will also save on time and labor compared with racking multiple

barrels or pulling multiple nails when sampling.

The world's largest

foeder belongs to the brewers of

the aperitif Byrrh, in France.

Though no longer operative, it

once held up to 1 million liters,

and required 200 trees over the

course of 18 years to complete.

Foeders

Foeders

Foeders

Foeders

Foeders

Chips, spirals and staves

Oak chips are an effective way of modifying and adding flavor to your

beer or wine - and chips are far cheaper and easier to manage than

buying new or used oak barrels.

Remember, chips float! Most brewers place chips into a clean sterile

hop bag and weigh the bag down with something heavy and inert.

Fitting a bag full of chips inside a secondary might not necessarily be

easy depending on what you use for a secondary vessel. Some people

add extra chips to barrels, while some utilize a stainless tank with a

man-way door.

Wood aged vs barrel aged

A lot of people use the term interchangeably. The simple difference is

that wood aged can also include chips, staves and spirals whereas barrel

aged implies the use of an actual barrel, puncheon or foeder.

Stored vs Aged beer – technically all beer rested in a wooden vessel or on

oak chips is aging with the intention to welcome changes and

transformations, whereas beer that is stored is typically in stainless

containers like kegs with no intention of further evolution of the product.

Wood aged vs barrel aged

How to increase extraction from the wood

- temperature

- time

- recirculation

- pressure

- surface area

Time: time impacts wood aging in a simple manner. The longer the beer is

contact with the wood, the more impact the wood has on the character

of the beer.

Temperature: temperature swings allow the wood to “breathe,” which

draws the liquid into the pores of the wood and out of them based on

when it is warm or cold outside of the barrel.

Recirculation: recirculation for the most part only happens in tanks or

totes, and is a form of agitation to achieve a stronger flavor transfer.

Wood aged vs barrel aged

Surface area: The surface to volume ratio gets smaller as the size of the

barrel increases. As the size of the barrel increases, there is less liquid

actually in contact with the wood.

Pressure: when pressure increases, flavor extraction increases.

Wood aged vs barrel aged

A good practice in wood aging beer is blending.

- Blending allows the brewer an opportunity to choose which characteristics

to highlight. For instance in sour beer, blending is often used to mix highly

acidic beers with less acidic beers.

- Blending also allows the brewer to have an opportunity for better

consistency. For instance, if releasing a barrel aged beer each year, the

brewer can choose to blend young vs older aged beers to work the product

towards a consistent brand identity.

- In some circles, blending is viewed as the most important process of aging

on wood. One bad apple could in fact ruin the entire bunch.

Blending

How often can a barrel be used?

- Typically most barrels are used only once or twice before being retired,

although this is not always the case. Keeping a stash of older barrels is a

great way to begin a sour program.

- Foeders and puncheons are often used for several generations, especially

in wild programs where yeast and bacteria can live in the wood and restart

fermentation when filled again.

- Even when barrels are done with beer, they often find secondary uses as

rain barrels, decoration, furniture or garden beds.

Blending

- it’s best to use freshly emptied barrels.

- If the barrel has been emptied a long time it may need to be opened up

and scraped. Scraping the inside will remove blisters, crystal deposits and

other debris that may be undesired.

Prepping

sulfur dioxide – sulfur sticks which burn like incense inside a barrel, will act as a

disinfectant to stave off a variety of unwanted microbes that might be native

to the wood.

Prepping

potassium metibisulfite & citric acid - The metibisulfite releases sulfur dioxide

into the water and the Citric Acid increases the amount of SO2 in solution by

lowering the pH of the water.

Lowering the pH can also keep out unwanted microorganisms. This solution

will keep the barrel sound

*When you treat a barrel in this manner, you will be stripping some of the oak

flavor from the wood.

Prepping

Things you’ll need in addition to cooperage

https://www.westernsquare.com/barrel-racks-breweries-1/

Things you’ll need in addition to cooperage

https://www.gwkent.com/bulldog-barrel-transfer-tube.html

Things you’ll need in addition to cooperage

Things you’ll need in addition to cooperage

Things you’ll need in addition to cooperage

https://www.gwkent.com/barrel-fermentation-plus-bungs.html

Things you’ll need in addition to cooperage

Things you’ll need in addition to cooperage

Things you’ll need in addition to cooperage

https://www.gwkent.com/short-strainer.html

Things you’ll need in addition to cooperage

https://www.gwkent.com/2in-sight-glass-tc.html

Things you’ll need in addition to cooperage

https://www.gwkent.com/turbine-flow-meter.html

Things you’ll need in addition to cooperage

https://www.gwkent.com/hoop-driver-for-oak-barrel.html

Things you’ll need in addition to cooperage

"Time does not respect what

is done without it."

Reputable sources

Reputable sources

Reputable sources

When brewing beer for wood aging, it is important to note that you

will end up with less volume than when you began.

Evaporation, leakage, soaking into the wood.

Always intend to brew a little extra for options when blending the final product.

Advice

Top off barrels often, especially after sampling or fixing a leak.

Aging beer in barrels is 100% about the ‘controlled’ oxidation over an

extended period of time.

Too much head space in the barrel could cause the beer to oxidize at a

rapid rate which could ruin that stout, or over-acidify that sour.

Advice

Expect occasional failure.

Things go wrong.

Barrels leak, bungs blow off.

The wrong bugs get in

Advice

https://www.keystonefermentationsupply.com/

https://www.riverdrive.co/

https://www.foedercrafters.com/

https://www.barrelsdirect.com/

https://www.thebarrelmill.com/

https://www.halfyankeeworkshop.com/blogs/news/aging-beer-with-wood

https://www.morebeer.com/articles/Beer_Wood_Oak