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The Flavors Of Oak In Rogue Spirits

Step inside Rolling Thunder Barrel Works and one of the first things you’ll notice is the aroma. A little sweet, a little smokey, it’s reminiscent of a campfire in the forest.

The smell is wafting from the back of the room where Cooper Nate Lindquist is toasting and charring barrels.

Rolling Thunder Cooper Nate Lindquist charring barrels.
Rolling Thunder Cooper Nate Lindquist charring barrels.

At Rogue Spirits, we’re blessed to have our legendary Brewmaster John Maier creating the wash for whiskeys, and to have Spirits Wizard Jake Holshue working his magic in the distillery. But as good as they are, one of the most important steps in crafting barrel aged spirits takes place after they’re done.

Which is where Nate steps in.

You could say that Nate’s job as a cooper is to build barrels, which is correct, but not the full story. His real goal is to capture all those wonderful oak aromas and flavors from the barrel, and infuse them into the spirits that John and Jake so lovingly created.

So every Rolling Thunder Barrel is both toasted and charred. The heat brings out the flavors of the wood, much like roasting does to a marshmallow.

Toasting

Toasting comes first. Nate starts small fires in metal buckets called cressets.

Nate starting fires in the cressets. The fuel is leftover oak from other barrels he crafted.
Nate starting fires in the cressets. The fuel is leftover oak from other barrels he crafted.

Then he slips a barrel over the cresset and lets the flames and heat ignite the wood’s intricate flavors.

Toasting is subtle and slow. The flavors produced during this stage are nuanced and complex. Depending on how long and how hot Nate lets the fires burn, he can create any level of toast ranging from light to heavy. Each has its own unique flavor profile.

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Charring

By comparison, charring is quick and dramatic. Nate lights the insides of the barrel with a blowtorch and waits until his nose tells him the char smells right. Then he sprays water into the barrel and covers the top to smother the flames. Timing is critical.

The start of charring.
The start of charring.
Dampening the fire.
Dampening the fire.

Charring leaves a thick layer of char on the inside of the barrels which, during aging, filters out impurities and unwanted flavors. It can also add flavors such as smoke and honey. Just like toasting there are different levels of char that vary with each cooperage. At Rolling Thunder, we have four levels and most often char to levels #3 and #4.

The heaviest char is sometimes called alligator because the inside of the barrel is blistered just like an alligator skin.

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What’s in oak that creates all these amazing flavors? There are hundreds of compounds that influence barrel aged spirits. Here are four of the most important.

Hemicellulose: Made up of sugars and other molecules. It breaks down during heating, caramelizes the sugars adding sweetness and toasty flavors.

Lignin: Contributes vanilla, clove and increases complexity.

Tannins: These add astringency rather than flavor. Astringency is that dry, puckery feeling in the mouth.

Lactones: Heating the wood increases the number of lactones, which add buttery and coconut flavors.

And finally, the type of wood also matters.

The wood we use to craft our barrels is native Oregon White Oak harvested from the Coast Range about an hour or so up the road from the Rogue Spirits Distillery and Rolling Thunder Barrel Works. Its flavor profile is unique among American oaks, and emphasizes clove and toast over other flavors.

Which means, the next time you try one of our Rolling Thunder barrel aged spirits or beers, you’re tasting something unlike anything else.

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