Across the whisky industry, many different types of oak casks are used. Here we explored the two major casks categories of ex-bourbon and ex-sherry casks. These utilize American oak and European oak casks, but what about other types of oak? Well, our OakY Series is here to explore all things wood and delve into the wonderful world of spirit maturation.
In recent years, as the whisky industry has evolved, distillers and coopers have started experimenting with different types of oak, and wood in general. Chestnut wood casks, Swedish oak, lemon tree wood; the experimental side of whisky is growing. In the East, there is a type of oak that is considered the most sought after and rarest variety in the world of whisky. The oak is called Mizunara, and it comes from Japan.
Mizunara Oak – Over $6,000 A Cask?
Mizunara is expensive, and for good reason. Any whisky releases even finished in mizunara always sell for much higher price tags, which tend to skyrocket on secondary markets. Suntory in Japan utilizes the oak for their distilleries, the most famous range being the Yamazaki Mizunara releases. Today, the Yamazaki Mizurana 2017 edition sells for almost $US10,000, when upon release it cost less than a third of that price. Mizunara sells, but what makes it so special?
- Two Century Wait: Well firstly, a mizunara tree must be at least 200 years old before it can be cut down and made into a cask. That’s a long time to wait, as the whisky will need time to mature within it as well.
- Leaks, leaks, leaks: Speaking to Hirotsugu Hayasaka, the ex-head cooper for Japan’s Nikka Whisky company, he says that mizunara oak is one of the hardest types to deal with. The staves are hard and so, difficult to bend and keep in place. The casks are prone to leaking and thus need regular maintenance. Compare to European and American oak, Hayasaka says mizunara is the hardest to deal with but it’s rarity and unique notes make is worth it.
- Extra 20 Years Wait: We see a lot of mizunara-finished expressions on the market, however, experts say that for mizunara to impact strong flavor on a whisky in must stay in the wood for at least 18 to 20 years.
- Coconuts & Incense: When a whisky has matured in mizunara long enough it delivers rich notes of incense, coconuts, banana, and a smooth, mouth-coating oiliness. Compared to other casks, these notes are very unique, and only imparted from mizunara.
Beyond the points above, what makes mizunara so expensive is the scarcity of it. Much like Japanese whisky, mizunara oak casks are incredibly difficult to find if you aren’t a large whisky maker in Japan. In fact, in Japan, the wood is sold at auctions where Suntory, Nikka, and other whisky producers go to get their annual quote of mizunara trunks. For outsiders, as one would imagine, it’s even more difficult and many Western distillers can’t even get their hands on the wood.
To date, mizunara oak is the most well-known type in the whisky industry, and the one that adds significant value to the whisky that matures within it. While there are certain varieties of oak across the globe that are, perhaps, more scarce, mizunara’s global image goes hand in hand with Japanese whisky’s and the lack of supply and increasing demand just makes all the more attractive to distillers.