Even as technology advances into more and more segments of the alcohol industry, one of the crucial parts of the process is still done the way it was perfected hundreds of years ago. Whiskey barrels are hand-crafted and provide an enormous amount of influence on the taste of the finished product. The crafting and production of the barrels in that sense is part of the art of making and perfecting alcohol.
The most common wood used for Whiskey barrels is American white oak. White oak is selected largely due to how leak-resistant it is and the flavors it imparts into spirits. Most whiskey barrels are produced in the US, where white oak grows. American white oak gives a vanilla, coconut and creamy type of flavor compared to European white oak which gives a dried fruit flavor with more spice. The wood is then cut into staves to minimize the chance of the wood warping and makes the barrel more water-resistant.
The staves are then placed in a belt-like iron hoop before being bent, typically by steaming to soften the wood, giving the signature curved shape of a whiskey barrel. The next step in the process is charring the barrel by firing flames inside it. This flaming extracts even more flavor from the wood, which seeps into the spirit during the whiskey’s maturations process. The aging process can last for a number of years depending on the brand and style.
Source: CNN, April 2017