How Oak Influences the Taste of Wine

Oak barrels are certainly beautiful to look at, layered in their rustic lofts at local wineries. However, the primary reason that good wine spends much of its life aging in barrels is far from merely co

Wine making: an illustrious art form

smetic. In fact, there is a rich history, as well as a thorough scientific reasoning, behind the process of using an oak barrel to influence and improve the taste of wine. It is an illustrious and challenging art form that has inspired vintners around the world ever since the first century.

Wooden barrels: a cooper’s genius

For thousands of years before the iron age, clay pots were widely used to store liquids. Fragile, heavy, and awkward to maneuver, they were far from ideal, especially for long voyages. Thankfully, clay got a significant upgrade around 800-900 BC, when iron age coopers accomplished the ingenious creation of the wooden barrel. These were made initially with wooden hoops, and eventually metal ones. However, the palm wood design was expensive and challenging to make airtight.

When the Romans came into contact with the Gauls during their conquest of Europe, they were thrilled to discover the oak barrel. These barrels were far superior to their clay and palm wood predecessors. They were significantly stronger and much easier to transport because of their ability to roll on their sides. In fact, Michael Veach, author of Kentucky Bourbon Whiskey: An American Heritage, described oak barrels as “the medieval forklift” due to their rugged and practical design.

By the first century, wooden barrels had become common household objects, used to hold everything from beer to olive oil. However, it didn’t take long for wine lovers to realize that the longer their wine sat in its storage barrel, the more flavorful and aromatic it became. Seemingly overnight, barrel aging was no longer merely a functional choice, but rather an avenue for a brand new craft. Today, barrel aging is still the primary avenue for perfecting good wine, because even with myriad advances in technology, it still accomplishes the best results.

Wine making: an illustrious art form

Before wine takes its lengthy nap in an oak barrel, it first must undergo the fermentation process. This involves a number of crucial steps, which, when artfully accomplished, contribute to fabulous wine. The grapes must first be harvested at peak ripeness, cleaned, and crushed. Yeast, tartaric acid, and sugar must be measured and gradually added, and the mixture must be carefully filtered. After several weeks and a couple of racking transitions, the wine is finally ready to be transferred to its wooden storage vessel. Choosing the perfect barrel for the aging process will ensure that the end result exemplifies the vintner’s art.

While a variety of different types of wood can be used to make barrels, the vast majority of wine barrels are made from oak trees. American oak is certainly respectable; however, French oak is widely considered the gold standard. Why are oak barrels exclusively used in wine barrel composition? There are two primary reasons: controlled oxidation and structural complexity.

Controlled oxidation: an oak barrel magic trick

When wine drinkers think of oxidation, they may panic just a bit. After all, oxidation causes wine to go sour, doesn’t it? Well, yes. While an uncorked bottle of wine will absolutely lose its character as it makes contact with oxygen in the air, ironically, controlled oxidation is actually a necessary part of the winemaking process. The difference, as the name suggests, is that the process is controlled. Oak barrel aging works because the porous nature of the wood very gradually allows oxygen to make contact with the wine held within. This gradual oxidation lowers astringency, provides deeper color, and develops a mosaic of fruity aromas. The racking process plays a role in oxidation, as well, but the wine barrel, itself, is of primary importance.

Structural complexity: a flavor euphoria

Oak possesses an extremely complex set of chemical compounds, which each provide their own unique flavor and texture to the overall composition of wine. Drinkers may detect hints of vanilla (provided by volatile phenols), tea and tobacco (from terpenes), or a sweet and toasty aroma (garnered from furfural). They will experience the subtle interplay of tannin gathered from the oak with the tannin naturally occurring within the wine. These, along with a variety of other essences, may be more or less present in the finished wine based on the type of oak, as well as the manufacturing process utilized by the barrel maker.

Some coopers use American oak, while others employ French oak. Some use a saw to cut the staves, while others hand split them. A variety of other factors are also relevant, including whether the staves are kiln dried or air dried, or whether they are boiled, steamed, or wood-fired before bending. The depth and color of toasting is also extremely important. Each of these variables affect the chemistry of the barrel and create unique flavor profiles to be imparted to the aging wine.

Barrel craftsmanship: a modern miracle

Given the complexity of barrel making and the craftsmanship necessary to accomplish an ideal wine barrel, coopers are often considered artisans as much as wine makers, themselves. In fact, to this day, modern coopers undergo a rigorous 7 year apprenticeship! Clearly, a great deal of training is involved in perfecting the art. It stands to reason, then, that wine barrels are highly esteemed, invariably reused, and frequently repurposed once their wine-making years have passed.

Rocky Mountain Barrel Company is a Denver-based curator of quality used wine and whiskey barrels from all over the world. From Scotch whiskey to Caribbean rum to Italian wine, we consistently stock the very best barrels to delight our discerning clientele. Whether you intend to craft your own wine at home or build an oak barrel dining table, our team of experts can assist you in locating beautiful, artisanal offerings for any purpose. Come in for a tour today, and discover the utter magic of repurposed oak.