Loading ...
Wood. The material that served as fuel for the first fires of early man, used to build what some believe was a vessel that saved all animals of the Earth, and purported by Virgil to have shaped the mighty “Wooden Horse,” that helped the Greeks defeat the Trojans around 1150 BC. Wood has been used for centuries upon centuries by modern day Man with countless uses, so it is no surprise that it has a long history in the production of one of Man’s favorite things – beer.
Although the largely diminished role wood plays in beer making today is much different than it was 100 years ago, wood is once again gaining serious recognition from brewers, the beer geek community, and better-beer lovers everywhere. Originally used more for storage and transport, wood, oak in particular, is now being used to lend its character to some of the most highly revered elixirs being produced around the world.
The invention of the barrel is dated to around 0 CE or just about 2,000 years ago, attributed to the various barbaric tribes people of Central and Northern Europe. It seems that by Roman times, barrels were in wide use in those areas. Wooden barrels were the storage vessel of choice for beer up until about the mid 20th Century. In an age where clean, light lagers began to dominate the market, shiny stainless steel became the preferred material, as opposed to wooden barrels, which were much more difficult to clean and maintain. Up until that time, in most cases, the barrels used for storage would be lined with pitch – an organic resin or wax, which created a protective barrier inside the barrel. This layer served several purposes: to help prevent the beer from coming into direct contact with the microorganisms that make a home inside the pores of the material, to protect against oxidation, to keep the wood from imparting its own flavor to the beer, and finally to help make cleaning and maintenance a little easier on the brewers. The exceptions to the rule are the sour ales of Flanders and Payottenland, Belgium, which we will get into a bit later.
These days, barrels are primarily used in the production of spirits and wine. There are a number of factors to take into account when deciding which barrel will be best for the type of beverage you want to age in it. Type of wood, how the barrel was made, size, and any previous use, all effects the final outcome of a liquid aged in a barrel. The barrels that are now preferred for use with beer are typically barrels that have already been used to age either spirits or wine. The flavors imparted by fresh barrels are way too strong and overpowering for the likes of beer.
The wood used primarily for barrel making is oak. Oak is strong and durable, easier to use and maintain than other woods, and adds a preferred flavor and aroma. Oak barrels impart upwards of 200 chemical compounds to its contents, but three are most important to take into consideration when tasting a barrel aged beer. Vanillin is a compound that will lend a vanilla-like flavor, aroma, and sweetness. Yes, this is also the main component from the extract of the vanilla bean. Tannins add a dryness, slight astringency, and acidity – characteristics that are common of red wines. Finally, compounds known as methyl octalactones add unique spicy qualities, depending on origin and type of oak used.
There are three varieties of oak that are now used for barrel production; most common for wine use is French Oak, otherwise known as Common Oak to arborists – either the European oak (Quercus sessiliflora), or English Oak (Quercus robur). French oak is highly porous in nature and is found near the great wine production regions, and is naturally used for the wine those regions produce. French oak tends to add more tannin, and the spice character lent can be distinctive of the forest the oak was harvested from. Some of these old growth forests have trees dating back to the times of Napoleon. When it comes to French oak wine barrels and their use in beer, think of wines and the flavors you might find in different types. A spicy Belgian style tripel or dry and herbal saison is perfectly complemented by the fruity acidity and light oak character of a Chardonnay barrel. Flemish reds, Lambic-esque beers, and American Wild ales are beautifully fused with the earthy tannic acidity of a merlot or Cabernet Sauvignon barrel. Every now and then, a brewer will put some other type of beer in a wine-barrel, giving the beer new life and putting an interesting twist on a style that might otherwise be common and all too familiar. Supplication, Sanctification, and Temptation, of Russian River Brewing Company in Santa Rosa, CA, are some of the finest American examples of wine barrel aged beers. Smoke From The Oak Wine Barrel, from Captain Lawrence Brewing Company in Pleasantville, NY, is also a delicious example of how a wine barrel can transform a “normal” beer into something divine.
The other main type of oak used for modern barrel production is North American White oak (Quercus alba). This type of oak adds high amounts of vanilla and a toasty character, suited best for spirits – Bourbon, whiskey, brandy, and rum in particular. Bourbon producers are by law required to use fresh barrels. When the barrels are emptied, distillers unload them at a fraction of the original price, and brewers snatch them up and fill them with their precious potions in order to absorb that sublime Bourbon character. Similar to French oak, White oak adds a spiciness that is particular to the state or forest the oak was harvested from, but this character is wider varied according to location. The stronger flavor associated with North American oak may also be due, in part, to the fact that the staves used to construct the barrels are sawn, as opposed to split like French oak. When the oak is sawn, it creates a rougher edge and more surface area of wood that comes into contact with the barrel contents. French oak, on the other hand, is split, creating a smoother, tighter seal from stave to stave. When it comes to American oak/Bourbon barrel aged beers, think of New Holland Brewing Dragon’s Milk with its silky smooth mouth-feel and smack of vanilla, or the rich, robust, tannic, and burnt espresso character of Port Brewing Older Viscosity. Founders Kentucky Breakfast Stout skillfully marries the flavors of Bourbon and sweet mocha-like roastiness of Russian Imperial Stout.
Finally, Hungarian oak (Quercus frainetto) is now being used in oak barrel production as well. Hungarian oak imparts a unique and highly peppery spice character, along with notes of mocha and typical vanilla character. I’ve found that aging on Hungarian oak can also impart delightful notes of fruit, cotton candy, and coconut that superbly complement the more traditional spicy vanilla flavors.
Another important factor in the amount of flavor a barrel will impart to a beer, wine, or spirit, is the level of toast or charring. During the cooperage process (a cooper is someone who builds barrels), the staves are set over a fire, heat is applied, and the surface is literally burnt, or charred. The more a barrel is charred, the more flavor the barrel will impart. Light to medium charred barrels are ideal for use with wine or lighter beers (think Belgian styles or sours). High or heavy toast will impart very strong flavors and aromas ideal for spirits, like whiskey, brandy, or rum. The rule of thumb for beer is strong and dark for barrels with a high toast. Russian Imperial Stouts and Barleywines are perfect.
While oak barrels are just now becoming popular in craft brewing, a couple of special types of ale, and the brewers that make them, have been utilizing oak barrels for hundreds of years and those traditions last to this day. In Belgium, the brewers in Dutch-speaking Flanders, and the lambic makers around Brussels, both brew beers where the use of barrels is integral to the final character of their products. Both of these types of ale, while quite different, use microorganisms during fermentation to create a truly unique character, which cannot be achieved by brewer’s yeast (Saccharomyces cerevisiae) alone.
Flemish red and brown ales are characterized by their sweet and sour flavor profile. To make these delicious and refreshingly acidic ales, the beer undergoes normal fermentation in stainless steel tanks with a mixed culture of yeast and bacteria. Along with Saccharomyces, Flanders ales are also fermented with Lactobacillus, and Pediococcus, which are both lactic acid producing bacteria. Once the beer is done initial fermentation, it is transferred into giant oak barrels called Foudres, which can hold up to 10,000 gallons. During this extended aging, the beer undergoes further fermentation by the bacteria and yeast. These beers are aged anywhere from 12-18 months, where they gain deep complexity and typically an intense tartness. This aged beer will then be blended with “young” beer, which mellows and rounds out the old soured beer with the sugars that have not been fermented during secondary aging. Oak is important to this process, not because of the flavor the wood itself imparts – these barrels have been mostly stripped of any oak flavor after years of use, some barrels are over a hundred years old – but because of the microorganisms which have made their home in the porous wood. These microorganisms can penetrate roughly a quarter-inch into the wood, and when a sugar source (beer) is added to a barrel with microorganisms, they will come out to feast, and in doing so will impart the particular flavors and aromas that the brewer is trying to achieve in the beer. The porous nature of oak also allows the slow diffusion of oxygen into the beer being stored, which is beneficial for the microorganisms to continue to live and do their work. Rodenbach Grand Cru sets the standard for the style, but Monk’s Café Flemish Sour Ale, New Belgium La Folie, and Petrus Aged Pale are all great examples of the wonderful ales produced by this region and method.
The lambic producers of Payottenland, Belgium (the area surrounding Brussels, Belgium), use oak for a similar reason to the Flemish brewers to their west, although the process differs slightly. Whereas Flemish brown and red ales tend to be associated with a “clean” acidity and flavor, lambics are known for their wild side. Lambic is brewed by producing an extremely protein rich wort (unfermented beer) that is then transferred to a cool ship after the boil, which is a long, flat container that exposes a large surface area of the liquid to the open environment while cooling overnight. The air around Brussels is known for its unique micro flora, a potpourri of saccharomyces, wild yeasts known as Brettanomyces, and various bacteria, which then settle onto the exposed wort. The wort will then be racked into oak barrels, where spontaneous fermentation takes place. Unlike Flemish sour ales, which start in stainless steel tanks, lambic will spend its entire life in oak barrels until it is packaged for sale. Lambic can be aged for years, and will often spend upwards of three years in a barrel. Over this time, the wild yeast and bacteria slowly do their work, bestowing the classic funky barnyard acidity that traditional lambic is well known for. While the cool ship and slow exposure to the natural environment is important for lambic production, it’s also important that barrels are used, for these barrels become home to the numerous microorganisms picked up in the air. Brettanomyces yeasts can actually feed on the natural sugars found in oak. Once introduced to the barrel, brettanomyces (and other bacteria) will forever be present and ferment any beverage it comes into contact with thereafter. For real insight into lambics, try some of the rustic sour ales from Cantillon, 3 Fonteinen, Boon, or Hanssens. They are truly eye opening.
While lambic and Flemish sour ale harkens back to ancient brewing techniques, it is a matter of debate as to what craft brewery first released a barrel-aged product to the public; in Radical Brewing, beer writer Randy Mosher sites Goose Island’s Bourbon County Stout as the first. Regardless of who did it first, barrel-aged beers are now the rage and gaining cult beer-geek status around the world. Currently, 20 of the top 50 beers on Beer Advocate are barrel-aged beers in one form or another. From the big and beefy Founders Canadian or Kentucky Breakfast Stouts, to the delightfully complex Supplication of Russian River, to the über rare Blueberry Blabaer Lambic by Cantillon, it’s clear that barrels have made their impact on modern beer culture. But will the trend last? If history is any indication, wood is here to stay.
