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Oak and Wine

chris wrote this on April 25, 2009

Hello Everyone,

I recently gave a seminar at the Great Grapes event in Cary this past weekend (4/18) on oak and its effects on wine. I had four wines to sample at the seminar; one unoaked and one oaked each of white and red wines. After the presentation I had the participants taste the wines and see if they could tell the oaked from the unoaked wines with their new found knowledge. Here is summarized version to share with readers of TraingleVino.com.

Wines and Oak

Oak reduces a wine’s fruitiness but adds tannin, structure, complexity, and clarity of color. The oak acts as a natural filter, drawing sediment and tartaric acid crystals to it surface while beneficial compounds are extracted into the wine.

There are two primary types of oak, French oak and American oak. Each adds a unique character to wines though experts agree that the marriage between French oak and wine is superior. French oak barrels can cost up to $1000 per barrel while American oak can be as much as $700. Spanish Rioja wines owe their unique aroma to exclusive aging in American oak.

The inside of oak barrels are “toasted” at one of three levels; light, medium, or heavy, depending upon the style of wine the winemaker looks to create. The heavier the toasting, the greater chocolate, toast, and coffee flavors in the wine but less oak tannin is extracted (the layer of char acts as a barrier between the wine and the oak surface).

Wines can age in oak barrels anywhere from 6 months to 5 years, depending upon the style of wine and the regulations of the wine growing region. Whites typically age for less than a year in oak, reds less than 2 years. Spanish and Italian reds can age up to 5 years in oak!

Wines can be fermented in oak as well as aged in oak. White wines are more commonly fermented in oak than red wines because red wines are fermented in contact with their grape skins which must be punched down to prevent an explosive build up of carbon dioxide (difficult to do in an enclosed barrel).

The “oak influence” of wines fermented in oak is less noticeable and more integrated than wines that are merely aged in oak. This is because the yeasts are able to process the compounds extracted from the oak along with the compounds in the grape juice at the same time.

Oak barrels are only good for a maximum of five vintages before the build up of wine sediment and tartaric acid crystals encrusts the entire inner surface of the barrels. These barrels can still be used to store wine, but the oak influence will be minuscule because the wine no longer interacts with the oak surface.

Many wineries “rack” their wines from newer barrels to older barrels after a period of aging so that they can use the newer barrel again for another batch of wine. The frequency of racking is sometimes expressed as a percentage on the wine label. For example, a wine that has been aged in 33% new oak has spent one third of its aging in a brand new oak barrel before being racked over to an older barrel.

Less expensive alternatives to oak barrels are soaking oak chips, oak staves, or even oak powder in the wine as it ferments or ages. In some cases winemakers add “oak oils” to their wines to mimic the effects of oak aging. These alternatives are not considered to be superior to oak barrels and in some areas their use is strictly prohibited.

It is very important that the winemaker balance the use of oak with wine flavor, acidity, alcohol, and natural grape tannins or the wine will be distinctively “oaky”.

White Wines

Oak adds nutty, almonds, toasty, burnt, vanilla, coconut, and butterscotch flavors & aromas to white wines. This also deepens the color of a wine to a more golden hue.

Red Wines

Oak adds spice, cedar, clove, smoke, leather, vanilla, anise, coffee, tobacco, chocolate, and mocha flavors & aromas to red wines. This also deepens the color of the wine to a more reddish hue.

It was interesting that the seminar participants could identify the oaked white wine 100% of the time but had more trouble identifying the oaked red wine. In many cases the participants had already associated “oakiness” as a fault in wines and therefore picked the wine they enjoyed the least as the oaked wine. In terms of American consumer tastes, it seemed that the majority preferred their whites unoaked while preferring their red wines oaked!

I hope you enjoyed this mini-lesson on the influence of oak in wines. I promise to return with more wine reviews next week!


Topics: reviews | 1 Comment »

One Response to “Oak and Wine”

  1. linda Says:
    May 2nd, 2009 at 12:39 am

    I learned alot about oak! You just take these processes for granted and then find there’s a lot more to them! I do enjoy a good white “oaky”. Keep up the wonderful reviews on wines and their regions . . . I really enjoy them.