Within the world of whisky, distillers utilize numerous types of casks. These differ depending on wood type, size, and the liquid previously held within. Each of these points greatly affects the whisky put in the cask, and alters the colour, depth, and final flavor of the whisky. Coming up, we’ll be releasing pieces on wood types and sizes, but first up we’ll be discussing the two most popular ex-casks in the whisky industry, ex-sherry and ex-bourbon casks.
Sherry vs Bourbon
The definition is simple- an ex-sherry cask was previously full of sherry, then emptied and filled with whisky. Ex-bourbon casks, previously held bourbon.
It seems simple, yet, these two casks types have come to lead the world of whisky. Sure, over the years producers have experimented with a huge range of casks. Ex-Cognac, ex-wine casks, ex-rum, and many more; but we’ll explore these later on. However, no matter what experimentation takes place, ex-sherry and bourbon casks reign supreme.
The US has created a very strong relationship with Scotland through whisky, with bourbon casks leading the charge. Why? Well, to produce bourbon the law stipulates that Virgin Oak, usually American oak, casks must be used to age the liquid. This keeps the flavor profile of bourbon where it should be, however, it also means that thousands of casks as discarded each day, as they can only be used once. This is where the relationship building comes in. These empty casks are immediately sent overseas, to Scotch whisky distilleries, Japanese whisky distilleries, and all the distilleries around the world that need ex-bourbon casks.
The notes ex-bourbon casks impart through maturation are soft, round, and smooth. The primary reasons for the bourbon casks popularity globally are:
- They are cheap and abundant, due to the bourbon industry’s aforementioned regulations.
- The notes imparted are sweet and smooth, and thus bourbon cask-aged whiskies can be added to blends, or bottled to cater to drinkers of less intense, smoother whisky.
When it comes to ex-sherry casks, the process is different. The European oak casks used to age sherry are of the highest quality and numerous famed distilleries pride themselves on the selections process they use. The Macallan distillery and Suntory’s Yamazaki distillery, two of the world’s largest premium single malt brands, fly to Spain and select the oak trees before they are planted. They purchase them and let them grow, before making them into casks, and filling them with sherry. Finally the sherry is emptied, and whisky is added in.
While bourbon casks are abundant and cheaper, ex-sherry casks are expensive and not as easy to get, especially the highest quality ones. After all, many of these sherry houses, witnessing the drop of sherry’s popularity worldwide, have signed exclusive partnerships with certain drinks giants. Why are ex-sherry casks so popular? Because they add numerous layers to whisky, from ruby dark colours to dried fruit and lively spice notes. In Asia’s strongest whisky markets, like Taiwan, Singapore, Hong Kong, and Japan, well-aged sherry cask-matured whiskies are positioned at the very top. The continent swears by deep, dark ‘sherry bombs’ as they are called- whiskies aged for long periods in ex-sherry oak, and thus bursting with intense sherry notes.
Beyond availability and pricing, the main draw of each cask type is the flavor profile it brings to whisky. While sherry cask-aged whiskies are more popular in the East, the US population loves bourbon and thus bourbon-matured expressions are easier to approach. When building your own cask portfolio diversity is key. In this way, trading years on will be easier with a variety of cask types and finishes within your repertoire.