Move over Amburana Wood finishes, here comes Mizunara

About a year ago I wrote an article on Amburana-finishes and how it was taking the bourbon world by storm. It seemed like everyone was getting their hands on the rare South American wood to add additional flavor to their whiskies. After trying several of them, the novelty had worn off and I started to see it for what it was: a finish that imparted way too much gingerbread and potpourri notes into whatever whiskey it touched. Even distilleries who reused Amburana barrels in an effort to lessen its effects still tasted oversaturated.

While Amburana finishes continue to be made, producers seem to be moving away from them. I don’t know if it’s because they aren’t selling as much as they used to or if its becoming harder to obtain barrels. My opinion on the matter is that finishing barrels have cyclic trends. Two years ago there was a big push for White Port barrels. Before that were Armangnac barrels. And before that were Sherry, Cognac and Madeira.

All of these finishes still exist, but at lower numbers than they used to in their heyday. This leads me to the topic of this article: Mizunara Oak barrel finishes surging in popularity. It’s the hottest finishing cask to pop up over the last 6 months. But its future may also be short lived because out of all the wood being harvested around the world, Mizunara may be the least sustainable of all.

A look at Mizunara Oak, where it comes from and how it’s harvested

Mizunara Oak – or “Water Oak” as its sometimes referred to – is a species that is native to eastern Asia, primarily in Japan. Most articles will tell you that a region in Hokkaido is the hotspot for finding these trees.

Visually, this species of oak doesn’t look anything like the white and red oak we have here in the United States. Mizunara doesn’t really grow straight and it takes at least 200 years (even up to 500 years!) before it can be harvested – a far cry from the 80 to 100 years that our domestic oak takes.

On top of that, the tree primarily grows in certain altitudes, making access to them a little more difficult to access and a lot more rare to come by. As such, the Japanese government heavily regulates how many can be harvested as well as implementing re-planting quotas to ensure future generations continue to grow.

Since the tree does not grow as straight and tall as oak in America and Europe, only limited sections of the trunk can be used for stave production. Usually these trunk sections are sold in 3 or 4-foot-long sections. The way producers go about obtaining this wood is typically through auctions rather than long-term contracts.

The process of buying Mizunara trunks has only gotten more intense (and expensive) throughout the years as more companies are vying for the precious wood. Furniture manufacturers have entered the fray along with architects and incense/fragrance producers. These have created thick competition to the cooperages.

*After drying for a year, Mizunara trunks are hand-split as their grain dictates*

If a cooperage does win the auction, they take their trunks to a drying yard where they are typically dried (seasoned) for a full year. Seasoning is a necessary and natural process that allows for the wood to shrink and settle into its form as the water evaporates from its structures. Additionally, chemical reactions occur at the microscopic level where certain elements soften. This changes the notes the wood will impart on any liquid that it will come in contact with in the future.

After the trunks are mostly dried, the wood is then hand-split into very rough staves before being stacked for additional seasoning – usually another two years. Cooperages that make barrels from American White Oak typically don’t season their wood this long. Some shortcuts exist for white oak where they can be cut into staves immediately due to the tight grain structure of the wood. From there, white oak is usually air (or kiln) dried for about a year. The difference between Mizunara and White Oak is that it’s essential for Mizunara to go through this lengthy seasoning process; White Oak is more forgiving.

Mizunara’s cellular composition doesn’t allow for typical cutting and shaping of planks. It has been attempted by some cooperages but was quickly found out to increase warpage. That led to leaky barrels. Now a handful of experts handle the splitting and shaping of the rare and delicate wood. It is more artform than industrial process. At the prices the barrels are going for, whiskey distilleries cannot afford to take any chances that expensive whiskey will leak from expensive barrels.

Why are we seeing so many Mizunara Casks now?

Recently, the American market has seen a large influx of producers using and releasing whiskies finished in Mizunara casks. I’m not including Japanese or Scottish whiskies in that statement either. There has been an influx of barrels and staves into the market recently even though the wood is controlled by strict regulations. On top of that, Japanese distilleries are also experiencing a surge in production now that new laws have been passed that outline the definition of true “Japanese Whiskey.”

I’m sorry to spoil this section of my article, but I don’t really have an explanation as to why we’re just now seeing more Mizunara Casks. The wood (and subsequently, barrels) is the most expensive its ever been. This should substantially raise the cost of any whiskey it touches. Yet most producers don’t appear to have huge price increases. If we are being told that Mizunara barrels are fetching $6,000 and if you can typically get 220 750ml bottles from each barrel (if it was topped off and has limited evaporation), then each bottle would have to carry a $27 upcharge at minimum. I don’t see that happening.

I can only speculate on what producers are doing to limit the cost of this rare wood. The first thing that comes to mind is that they’re re-using them. This is relatively common in the Scotch Whisky world and has even been repeated here in the United States with producer “re-charging” a barrel. With Mizunara, they may toast the barrel, use it for finishing whiskey, then dump it and give it another toast (or char) to see if they can wring any more life out of it.

Another (more controversial) way producers are obtaining these barrels may be through some less-than-legal methods whereby illegally harvested Mizunara wood is ending up on the market. Foreign companies (American, European) might be unwittingly purchasing their wood/barrels this way or perhaps they just turn a blind eye. This could explain why producers are getting their hands on unassembled wood pieces and sending them to a country like Germany (where a lot of these barrels are coming from recently) to be assembled. The German government would have little incentive to question the source of wood obtained from outside their borders.

If you think I’m being too dark with my assessment, just know that all of this has already been happening with Amburana wood. What was supposed to be a tightly-controlled export system of that wood has been easily avoided by moving the wood through neighboring countries who act like a middleman to eventually export the wood all around the world. Just because Japan doesn’t have a neighboring country to easily move goods through doesn’t mean they don’t have criminal syndicates that can make this kind of thing happen. Ever heard of the Yakuza?

What makes Mizunara an appealing bourbon to finish bourbon in?

One of the tough things to do when finishing a bourbon is to find a cask that doesn’t overwhelm or get covered up by the strong bourbon notes. Wine barrels have typically been a good option while toasted barrels sometimes aren’t strong enough to detect. Amburana wood is too overwhelming and makes you think you’re drinking a spirit other than bourbon.

But Mizunara is different. It doesn’t try to overwhelm or underwhelm any liquid it touches. It simply adds some complimentary flavors that you can’t usually find through aging with White Oak. What flavors? Typically coconut, sandalwood and honey are the most common. These delicate flavors adds a new dimension without the polarizing effect of turning away a lot of drinkers. It’s considered inoffensive. But its exotic nature gives any whiskey a classier aura that lures people in. Out of all my enthusiast friends, nobody has a negative experience with Mizunara-finished whiskies. That’s something I assume product developers have noticed, too.

Downfalls of Mizunara barrels

It’s not all sunshine and roses when it comes to Mizunara finishes. Producers have found a high amount of leakage that can occur. I already covered the methods coopers use to try and limit leaky barrels but the truth is that no method is 100% foolproof. Mizunara barrels carry some of the highest failure rates of any wood barrel. Couple that with the highest cost to obtain a barrel and you’ll see why producers aren’t exactly rushing out to make huge quantities of finished whiskey with it.

I know I touched on this before, but the price of these barrels is going to make every drop of whiskey it touches a premium product. I’ve never seen any 100% Mizunara finished whiskies below the $100 retail price point. This means that if you want to experience the taste of this rare wood, you’re going to have to pony up the cash. And for some, they might be disappointed that the flavors and scents aren’t noticeable enough for them to consider it “money well spent.” Today’s whiskey enthusiasts are more into big, bold flavors and Mizunara just isn’t the type of wood to deliver that.

Conclusion

Now that you know everything there is to know about Mizunara finishes, do you want to try it? If so, I’ve compiled a list of American Whiskies (Bourbon, Rye and more) that have seen time resting in these rare barrels. Please note that some of these companies may have only had limited releases so extra work may be required to track down a bottle.

Barrell Craft Spirits (Vantage, Cask Finished Series: Mizunara)

Jefferson’s (unknown release)

Taconic Distillery: Cask Strength Bourbon

Rabbit Hole: Founder’s Collection

Four Gate: Majestic Wood Series “Japanese Mizunara Oak”

World Whiskey Society: 15 Year old Kentucky Bourbon finished in Japanese Mizunara Oak Shochu Barrels

Starlight: Single Barrel Bourbon finished in Mizunara Barrels

Broken Barrel: Limited Edition Mizunara Whiskey

Frank August: Mizunara Finished Bourbon

Angel’s Envy: Mizunara Cask

Heaven’s Door: “The Bootleg Series: Mizunara Oak

Charter Oak: Mongolian Oak (While technically not true Mizunara Oak, it is very closely related)