The Importance of Wood in Whiskey

We have always felt we have the area's most extensive liquor selection, and we pride ourselves on having a wide variety of whiskeys to choose from. From bourbons, Irish, Canadian, Scotch and blends, we're sure you will find a favorite whiskey here!

All of these years working with these products, it has always been on my travel bucket list to visit a distillery where these spirits are made. I think it would be quite interesting to see the whole process. The art of making whiskey, despite starting with the simplest ingredients, becomes a pretty in depth operation.  There are many factors that are important in coming up with the consistent flavors every time. I recently read an article on this process and how it all works, and one of the most important factors of the finished product is the wood casks that stores and ultimately flavors the whiskey.

Whiskey is created with 4 basic ingredients; grain, water, yeast and wood. The alcohol process evolves with the grain, water and yeast, but the wood is what contributes anywhere from 50 to 80% of the aromas and flavors to the spirit. The type of whiskey grain, time spent in the wood and the climate in which it is stored, all greatly affect the finished product. Different whiskey requires different wood and different time spent in the wood. Most of the time needed is at least a 2 year storage for bourbons and 3 years for Irish and Scotch whiskeys. However, as you know, you will find some 5,10, 20+ years out there, and those flavors reflect.

Historically, any type of wood could be used for the maturation of whiskey.  But now, law dictates that casks storing whiskey must be constructed of oak.  A symbol of strength, oak is selected for being tough yet easy to work with.  It has tight grain that prevents leaking, is porous and allows oxygen in and out of the cask.  Plus, it can be bent by heat without splitting.

Although there are many different varieties of oak out there, there are only a few that work best for maturing wine and spirits. Unlike fine wine where as it is bottled, it ages and matures, whiskey needs its time to rest in these oak casks in order to get the full flavors the distillers desire. Wood is full of naturally occurring oils called vanillins. It is these oils that are drawn out of the cask by the spirit and over the period of maturation, they add to the whiskey’s flavor profile.

Here are a few things to know about comparing which oak is used:

American vs. European Oak
European oak is more easily penetrated by liquid, especially spirits, and allows greater oxygen flow. American oak is lower in tannins. In the simplest of terms, American oak has stronger flavors than European oak. American oak has only been used in the whiskey industry since the end of the WWII. At that time, the Cooper's Union and lawyers formulated the law that stipulated that all American whiskey had to be matured in new wooden casks. This was done to boost the coopering industry that had collapsed during Prohibition in the 1920s and 30s.

Previous Use and Oak Virginity
Oak’s influence is first determined by the type of oak, its previous use or virginity, where it was grown, when felled, how it was dried, how it was cut, and the cooperage (how the barrel was made).This is of great importance for both Irish and Scotch whiskeys. The two most popular types of used casks utilized for whiskey maturation are Bourbon and Sherry casks. Many falsely simplify the discussion by stating that Sherry casks come from European oak while Bourbon casks are made with American oak. About 90% of all the Scotch malt whiskey ends up in casks that have contained bourbon before they were shipped from the United States.

The fact that a spirit matures in oak casks was only discovered by accident. Historically, the wood casks were only used to store the spirit for a short period of time. It was most often consumed long before it could extract any flavors or color from the wood. Once this discovery was made, the importance of the wood used for maturation really came to the forefront.

Next time you are enjoying a neat glass of one of your favorites, just think of the process that is involved in its creation. It has sat, undisturbed for 2+ years in a wooden barrel. Or try 2 different styles side by side and see if you can taste the difference. !