Oak has been used for thousands of years as a wine vessel. Going back to Roman times, it was an inexpensive and durable container for transporting wines over land and by sea. And, today, oak remains and important wine vessel.

Oak barrels are sometimes used during a wine’s fermentation process and regularly during the wine’s aging process. Both of these uses of oak imparts flavors to the final product.

The two most dominate types of oak used in winemaking come from France and the United States. Each adds its own unique flavors. French oak is known for adding nutty and smoky flavors. American oak’s dominate flavors are vanilla and coconut.

The flavors from oak are also enhanced by the “toasting” process in which the open-ended barrel is placed over a flame such that the interior of the barrel is heated to the point of either a light roasting of the wood or a complete charring of the wood. Winemakers order their oak barrels to be either light, medium or heavy “toast” in order to get just the right flavors for their wines.

Another factor affecting the flavors from an oak barrel is its age. When a barrel is new, it will impart more and stronger flavors into a wine. But, an older barrel that has been used two or three times may be referred to as “neutral” but will still add texture to a wine while preserving the fruit flavors, and yield more subtle flavors. Use of a combination of both new and older “neutral” barrels is also very common when a wine maker wants to ‘dial in’ a specific set of flavors.

And, while oak’s use in the making of red wine is common, its use in the making of white wine is less common. The most notable use of oak in the making of white wine is in the production of Chardonnay, especially California Chardonnay. A heavily oaked Chardonnay will take on buttery flavors, like popcorn and toffee. In fact, the connection between oak and Chardonnay is such that oak flavors are often used as a way of blindly identifying the grape itself.

Oak barrels also affect flavors in wine due to the fact that it is porous to oxygen. Oak allows oxygen to very slowly enter the barrel which, over time, results in making a wine taste smoother and less astringent.

Finally, winemakers must decide whether to ferment and/or age their wines in oak. Fermentation and aging in oak barrels yields greater integration of flavors than by doing fermentation in steel tanks and then aging the wine in oak barrels.

So, there’s a little bit about oak and how it flavors your wines. Cheers!