Japan's Mighty Oak

How a gnarly old Japanese tree took over the world of whisky.

- Jonah Flicker

The whisky world can be susceptible to fads and hype – indeed, a certain degree of gimmickry is to be expected in a market as crowded as this one. The current obsession, as you’ll no doubt be aware, is cask finishing, where the liquid is transferred to a different barrel after its initial ageing – one that previously held a fortified wine such as sherry or a spirit such as rum – to impart another layer of flavour. But this is where things get interesting. Of late, a particular type of wood, the finicky Japanese oak tree known as mizunara, has become the flavour of the month, so to speak. And this time, it’s actually worth the hype.

Like cask finishing itself, which The Balvenie pioneered decades ago, mizunara oak isn’t exactly new to whisky, at least in Japan. For instance, since its launch in 1984, one of the foundational components of Suntory’s Yamazaki Single Malt has been whisky aged in mizunara casks. The tree’s use can be traced back to World War II, when bans on exports to Japan meant that the nation had to rely on its own trees despite the fact that mizunara oak can be frustratingly difficult to work with. The name translates to ‘water oak’ due to the high moisture content of the wood, so it needs extensive drying before being turned into barrels. The trees come from the Hokkaido region, where they’re a protected species, thus the Japanese government regulates how many can be logged. On top of all that, the price of mizunara barrels has skyrocketed in recent years.