Barrel

Jason Sledd's barrel and bulldog

in progress

Barrels are an ideal vessel for fermenting many funky and mixed-fermentation beers. This page discusses the sorts of barrels and barrel alternatives available to pro and home brewers and influences those barrels have on the final beer to help brewers choose the barrel or barrel alternative that is right for them.

Types of Wood Used in Barrels

The type of wood used to make a barrel can impact both the flavor compounds that the barrel can provide as well as the rates at which gasses (O2) are allowed to penetrate through the wood. The characteristics of a given wood are dependent on the species used but also on factors such as more local conditions where the wood was grown in addition to the seasoning and toasting process. Toasting is discussed further in its own section below.

Acacia

Acacia wood, also known as "Black Locust," is a species of tree native to the southeastern United States - although its roots have spread worldwide, from Europe all the way to Asia and as far south as Southern Africa. More recently, Acacia has been used as an alternative to the traditional white oak when aging White wine.

Although white wine is often aged in steel casks, wine makers have since discovered that aging in an Acacia barrel preserves the wines aromatic and fruit characteristics. Acacia wood does not contain as much tannin content as oak, thus, it better preserves freshness as well as floral and varietal characteristics. Additionally, white wines aged in Acacia barrels do not suffer from a loss of overall structure.

Acacia is predominantly used in applications for furniture and flooring, however, its physical and chemical properties have led this wood variety to become an integral material within the wine industry: Acacia wood is ideal for aging White wine.

American White Oak

American White Oak (Quercus alba) is regarded as one of the preeminent species of hardwood grown here in the United States of America. This species of White Oak has tyloses, an outgrowth of the parenchyma cells which stems from a reaction to natural stresses in the environment such as drought; which gives the wood a closed cellular structure, making it water- and rot- resistant. This closed structure also results in less air transfer through the wood than other oak types such as French oak.

Within the Wine & Spirits industry, Quercus Alba or American White Oak is the primary source of material in the production of Whiskey barrels (especially in the case of bourbon, which is legally required to be aged in charred new oak barrels). What makes this species of wood key to the whiskey industry is it chemical structure and the effect this imparts on the aging whiskey. American White Oak is known for its high vanillin content, oak lactone (coconut/bourbon characteristic), and wood sugars which all affect the bourbons taste. Additionally, American White Oak affects the coloring of the bourbon itself. Impure wood varieties like Pine contain resin canals which pass strong flavors into maturing whiskey. Note that the char levels in some spirits barrels might make them a less ideal candidate for many mixed-fermentation beers. In addition, some bourbon barrels are not constructed as sturdily as wine barrels , possibly due to the inability of producers to use barrels for many subsequent batches of bourbon (as would be common in wine).

French Oak

French oak (Quercus sessilis/Quercus petraea and Quercus robur)-----. French oak contributes comparatively more trans-3-Methyl-4-octanolide while American oak contributes more cis-3-Methyl-4-octanolide to beer . These lactones both contribute a coconut character but the cis-lactone has a much lower flavor and aroma threshold , therefore American oak barrels may give more of a lactone flavor and aroma impact. Q. sessilis is more common in wine aging and Q. robur is more common for cognac barrels

Hungarian Oak

(Quercus frainetto)

Chestnut

Chestnut (Castanea sativa) can be a cheaper alternative to oak for barels. Chestnut barrels are used by some lambic producers (though generally most lambic barrels are oak).

Barrel Alternatives

in progress

A number of wood products are available to homebrewers to get wood characteristics without using a barrel. While barrel flavors are generally not the primary goal of funky beer brewers who use barrels for fermentation and aging, wood can contribute some of the additional characteristics that barrels offer (such as mouthfeel influences) and can also be used to house microbes in a similar way to a barrel (Vinnie's dimebags). The most common non-barrel wood products available to brewers are oak based.

Chips - Oak chips maximize surface area and have less variability in the depth of toast. Oak chips are not ideal because if the brewer is after flavor contribution chips will be more one dimensional and if the brewer is not after a wood flavor contribution, oak chips will give faster flavor extraction than other options and will therefore not give the other benefits of oak as well as other products.

Cubes - Oak cubes are readily available to brewers. They offer greater toast complexity and a lower surface area to volume ratio than chips. (reference Vinnie's dimebags, amos oak in primary)

Rods - Rods offer a similar product to cubes however the surface area to volume ratio is even smaller. In addition, rods (and lumber) are the primary source for alternative woods. See John Gasparine's 2013 NHC presentation on alternative wood aging (AHA membership required).

Spirals - Wood spirals are basically rods that have been shaped to increase the surface area. They offer the same potential benefit as rods and cubes in dimension of toast flavor. Based on faster flavor extraction than rods, spirals may not be the ideal choice for brewers looking for the non-flavor benefits of wood.

Honeycombs - Honeycombs are similar to oak spirals in what they offer and they maximize the surface area even more.

Lumber Stores - Some woods traditionally used in barrels such as oak go through a prolonged curing process before being formed into a barrel and toasted. If you are trying to use one of these woods, be aware that just getting wood from a lumber store and toasting it yourself will not give the same results as properly cured woods used to make barrels and barrel alternative products. Lumber stores can be good resources for finding some 'exotic' non-traditional woods to use in their beers. For brewers interested in this we recommend this presentation from the 2013 National Homebrewers Conference given by John Gasparine (must be an AHA member to access). Note that some woods may contain compounds not safe for consumption so be careful and research your woods before you use them.

Toast level and Volume

In progress

Barrels and barrel products are generally available in toast levels of light, medium, medium+ and heavy as well as varying levels of char. in addition to different wood types, different toast levels each have their own characteristics and are chosen for different purposes. Barrels used for aging spirits such as whiskey generally have some degree of charring, or at least heavy toast, while red wine barrels may be more commonly in the medium or med+ range. While the homebrewer and professional brewer does not always have full control over the toast levels of the barrels that they are getting (as the barrels are frequently used by wine and spirit producers before being acquired by brewers), brewers will likely find that different toast levels are better suited different beers.

Some brewers select specific barrels based on what they previously held as a fundamental component of certain beers (e.g. Russian River, Cantillon 50N, 3F Zenne). In addition, sometimes brewers aren't looking for barrel flavor in their sour beers and are more interested in the medium that barrels provide for fermentation in addition to some less flavor active compounds that barrels may contribute (--source: Jay and Tim Clifford for on the sour hour, probably something from JvR). Due to the delicate balance that good mixed-fermentation beers have, an aggressive barrel character may not always fit and brewers will have to get a feel for their barrels to know how long it takes for a beer to develop appropriate barrel character compared to how long until it develops the right fermentation character. For a first fill, it is recommended to taste the beer regularly to see how it is developing, and it may be necessary to allow additional aging in other vessels like carboys or stainless tanks for the beer to arrive at the right level of both fermentation development and barrel that the brewer is targeting.

---flavor description table to come (see also the flavor descriptions for different wood types above)----

Barrels are also available in a number of different volumes. Typical volumes of wine barrels are around 228L (60 gal) and may vary slightly depending on region and cooper. Professional breweries generally use barrels of this volume and larger. For homebrewers, filling a barrel of such volume can be a bit more tricky and may require a group effort and/or many brews. Some smaller barrels are available for homebrewers via craft distillers (among other producers). These barrels which can be found in the 5-15 gallon range provide an attractive option for homebrewers though some special considerations may be needed.

First, smaller volumes mean a greater surface area to volume ratio. This means that both flavor extraction from the barrel will be faster and O2 pickup will be greater (as oxygen penetration is tied to the barrel's surface area). Both of these factors make these small barrels attractive to craft distillers as they can shorten the aging time for certain flavor developments, but for the homebrewer looking to produce long-ages mixed-fermentation beers with no barrel flavor impact to supportive barrel character rather than strong barrel character this is not ideal. The barrel character can be partially stripped by repeated use and soaking with water. Because many of the small barrels available to homebrewers are derived from distileries and therefore may be more likely a heavier toast level, it may take longer to remove the character of the wood and a progression of beers may be needed to make the barrel appropriately neutral for long aged sour beers .

Second, the staves of smaller barrels are generally thinner allows greater oxygen permeability. So smaller barrels, both by surface area to volume ratio and by generally thinner staves, allow greater O2 transfer to the beer than larger barrels. Homebrewers may wish to counteract this O2 transfer by waxing smaller barrels .

Barrel Care

in progress

Storage

Empty

Full

Misc Info

• Barrels used by some lambic producers (notably 3 Fonteinen and De Cam) were originally 4000 liter barrels used by breweries like Pilsner Urquell. The barrels used for lager brewing are pitched. However, they were rebuilt to hold 1000 liters, and the pitch was removed before being sent to lambic brewers in Pajottenland .
• Potassium bitartrate (KHTa) is formed in wine, through the reaction between the bitartrate ion (HTa-), from tartaric acid (H2Ta), and the potassium ion (K+) found in grapes, especially grape skins. It is also known as potassium hydrogen tartrate, and commonly called "Cream of Tartar", "wine crystals", potassium salt of tartaric acid, tartrates, argols, tartres (French), Weinstein (German - "wine stones") . KHTa build up appears as crystals in wine barrels. It has no affect on the taste of wine, and is assumed to have no affect on the taste of beer . They can be removed from the inside surface of barrels through cleaning with Proxycarb™ or another sodium percarbonate based cleaner such as scent-free Oxyclean™ (see the Barrel Builders Barrel Maintenance Repair Manual).

General Resources and Articles

Maintenance and Repairs

• Barrel Maintenance and Repair Manual, by Barrel Builders, Inc.
• Master Cooper Douglas Rennie at Seguin Moreau Napa Cooperage - Repairing Barrel Leaks Video
• American Lambic Blog - Barrel Maintenance for Lambic Brewing
• Citric Acid & Sulfite Barrel Preparation; M&M Wine Grape Company.
• Keeping It Clean - Barrel maintenance for those new to oak barrels; BYO article.
• Barrel Maintenance and Storage, Farmhouse Beer Blog.
• Funk Factory Geuzeria - Pyramid Stacking Technique for Barrels
• From End Table to Aging Vessel: Reconditioning an old barrel. Ale of the Riverwards Blog by Ed Coffey.
• Ryan Steagal's video of repairing a hole in the side of a barrel.
• Cleaning barrels with Gordon Schuck of Funkwerks

Racking Canes

• Bulldog Mfg
• GW Kent Bulldog
• My Pressure Racking Cane, A Beer Diary blog.

Barrel Taps

• Funk Factory Geuzeria - Barrel Tap.
• GW Kent Oak cask Fitting Adapter.

Bungs

• Alasco Rubber & Plastics Corp.
• Vin Table LLC

Waxing Small Barrels

• Paraffin waxing a barrel, Funk Factory blog article.
• Great Fermentations Blog - Waxing Smaller Barrels with paraffin wax.

Embrace The Funk Tips

• Barrel Cleaning and Storage
• Barrel Repairs and Maintenance
• Barrel Filling Procedure

Vinnie Nail

• Burgundeon Babble Belt Forum post by B-Dub that shares an email from Vinnie regarding his nail technique.

Milk The Funk Tips and Discussions

• Dave Janssen's discussion on MTF about a CO2 Pressure Racking Cane for Barrels, with tips from Eccentric Beekeeper
• Ed Coffey's Cheap CO2 Racking Cane discussion on MTF
• Discussion of equipment for transferring out of pyramid stacked barrels and tap fittings.
• Autoclaving Alasco bungs.
• Toasting your own oak cubes

Sourcing Barrels - Manufacturers and Suppliers

Pro Sizes

• Black Swan Barrels.
• East Coast Wood Barrels.
• Rocky Mountain Barrel Company.
• If you live in a wine producing region, meet your local winemakers and join local winery forums to see what sorts of used stuff comes up.

Offers Smaller Sizes

• Oak Barrels, Ltd.
• The Barrel Mill.
• Corsair.
• American Barrel Exchange.

Homebrew sized used barrels

• Woodinville Whiskey Co - 8 gallon barrels used for whiskey aging
• Balcone's 5 gallon spirit barrels - The homebrew supplier for Balcone's 5 gallon spirit barrels

See Also

Additional Articles on MTF Wiki

• Foeder

External Resources

• "Anson on Thursday: Oak ageing holds key to wine sweetness", an article on analyzing oak on a molecular level for desired qualities.
• BasicBrewing radio interview with CJ Shamus; great information on using small barrels for a sour beer program.