It is almost impossible to talk about wine without mentioning oak. These two go hand in hand since one makes the other a lot better. Yes, you guessed it. Oak gives more flavor and structure to the wine. Just like most discoveries, oak as a flavor-adding component to wine was completely accidental. Oak would only be used to transport wine from the winemaker’s estates to either the Royal families or to the rich. It was much later that wine producers realized that these barrels added flavor, aroma, and complexity to their creations. A welcome surprise, with the wine, gradually becoming better with time. Oak has been used in winemaking since medieval times.
Oak has quite a long relationship with wine. It has become a seasoning for wine. It adds flavor and aroma to wine, making it delicious, flavourful, and seductive. Its pores allow for the slow intake of oxygen, helping make the wine smoother and less harsh. Oak provides a favorable environment for particular metabolic reactions to take place (such as malolactic fermentation), this is why wines that have been in oak are creamier.
Both red and white wine varietals benefit from exposure to this natural seasoning. They include: Pinot Noir, Cabernet Sauvignon, Merlot, Pinotage, Chianti, Zinfandel, Nebbiolo, Tempranillo and Syrah. White wine varietals that reap these benefits include Pinot Grigio, Pinot Blanc, Sauvignon Blanc, Semillon, and Chardonnay.
Structure of Oak
Because winemakers should not add additives to their wines, oak has become the best way of affecting its taste. A large proportion of oak is hemicellulose, which acts as a binding agent in the wood itself. The oak comprises small sugars such as xylose and arabinose. Not only can these sugars be hydrolyzed when in contact with the wine, but they decompose when toasted, forming compounds like furfural, maltol, and ethoxylation which can give roasted, malty, and caramel notes.
When choosing the type of barrel to use in their aging and storage, winemakers have several things to put into consideration. The most important being the value and uniqueness of the end product. To get the desired results from the type of oak to use, some factors put into consideration include:
- Where it is from
- How you dry it
- The way you toast it
- The way individual barrels were used before
- The length of time the wine ages in it
Where the oak is from
The barrels used in winemaking come from two main regions; America and France. Popularly, French and American oak. Although these are the most common types, Slovenian and Hungarian barrels are being adopted by some winemakers. Each type of barrel has its advantages and disadvantages. American barrels, for example, are cheaper than their French counterparts and tend to have a bigger impact on a wine’s flavor and aromatic elements. French oak barrels are, however, known as the wine industry’s best barrels. This is because they offer higher wood tannins and tighter wood grains. This tends to have less influence on the wine’s flavor, instead of contributing more to the wine’s overall palate presence. However, they are considerably more expensive, costing almost three times the price of their American counterparts.
Concerning age, the newer the barrel, the more concentrated the oak’s influence will be on the wine. As such, winemakers who want to add stronger oak flavors in their wines spend considerably on barrels. Some producers, however, will age a portion of the wine in new oak to impart some flavor and complexity, before blending it with the rest of the wine which was in older oak, giving the wine some character, while saving on barrel costs. This means that one-third is put together with wine that was in the old barrels, increasing the overall complexity of the wine when blended before bottling. This drives down oak costs while giving the wine oaky characters.
Older oak barrels are still able to provide some more subtle flavors, however, and they continue to play a role in as far as oxygen is concerned. While oak holds liquid without leakage, a minuscule amount of oxygen can permeate the wood. This has a big impact on the natural chemical conversions that wine undergoes during fermentation and maturation.
The size of the barrel matters a lot. The smaller the barrel the greater the impact the oak will have on the wine, because of the surface area to volume ratio of wine and the wood. As such, finding a balance of age, oak provenance, and size to output can be a complex mathematical equation where costs are concerned.
Degree of toasting
After choosing the type of oak, a winemaker will decide what degree of toasting is appropriate for the wine’s style. Barrel toasting can be light, medium, or heavy. A lighter toast retaining some of the oak-based characters for the wine and heavier toasting gives rise to more oaky and smoky tones in the wine. By increasing a barrel’s toasting, you’ll effectively increase the oak’s influence on the wine’s color, aroma, flavor, and overall style.
The length of time the wine ages in oak
How long wines are aged in oak depends entirely on the winemaker’s intention for the wine. It usually takes several months for you to feel the characteristics. Some typical aging periods however are:
- Pinot Noir: 10 months in old French barrels
- Chardonnay: 13 months in 50% new French barrels
- Gran Reserva Rioja: 24 months in 40% American and 60% French barrels
- Zinfandel: 17 months in 20% new American barrels
The way individual barrels were used before
As innovation is the order of the day, the wine industry has innovations of its own. In Australia for example, one of their major wineries had been experimenting with aging wine in whisky barrels. This has recently given birth to the double-barrel range of wines. What happens is the wine is aged in oak as usual. This helps refine the tannins and rounds out the smooth sweetness at the front palate, thanks to the naturally-occurring vanillins in the oak. After maturation, the winemaker pours the wine into a second barrel, a whisky barrel. What the second barrel does is give the wine an extra level of depth and character.
In America, one winemaker surprised the world when he decided to use whisky barrels from some of the best distilleries in the country, because of how hard it was to find French barrels. He aged his Zinfandel in small, whisky barrels. This process imparts delicious slathers of charred vanilla and caramel on the wild black-fruit palate of the 1000 Stories.
Oak has been used for centuries with wine. First as a means of storage and transport of the elegant drink. To the discovery that it is a source of seasoning for the wine that is put in it.
Does Oak make bottle corks? Yes, the material used in corks comes from oak. That is why some bottles are aged for more than two decades.
