Amburana trees, sometimes referred to as Brazilian oak, are native to South America. iStock / Getty Images
Native to the dense jungles of South America, the tall, slender amburana tree can be found growing in Brazil, Argentina, Peru, and Bolivia. Though it’s sometimes called “Brazilian oak,” amburana actually belongs to the legume family, making it a relative of chickpeas and mesquite rather than oak.
These trees, which can reach heights of 100 feet, have traditionally been tapped as a source of timber. Amburana wood is fairly light—nearly half the weight of oak—and has a tight interlocking grain that offers good liquid retention. Brazilian distillers have long used amburana casks to age cachaça, and American brewers have also experimented with them. In recent years whiskey makers have started using the casks as finishing vessels.
In 2019, Vermont’s WhistlePig became the first distillery to release an amburana cask-finished whiskey. Chief blender Meghan Ireland initially heard about the wood through its long and storied history for aging cachaça, and acquired a cask in late 2018. The resulting whiskey was the 12 year old Old World Amburana Cask, an aged rye that was finished for just 1 week and bottled in very limited quantities as part of the experimental Single Finishes program. That cask was later reused to finish Boss Hog VII: Magellan’s Atlantic, which spent 3 days in amburana.
Plenty of other whiskey makers, like Barrell Craft Spirits (BCS), Penelope, Four Gate, and Starlight, have since followed suit, entranced by the very distinctive flavors from this wood. It imparts very strong notes of cinnamon, nutmeg, chestnut, cloves, and vanilla to the whiskey—Ireland calls the flavor profile “Christmas in a drink.”
Amburana casks are fairly similar to oak barrels in terms of porosity, but require more monitoring of the finishing process, because they contribute flavors very quickly. Those flavors can start impacting the whiskey within days, and can quickly overpower it if left unchecked.
“The overall goal is to make sure that all of the underlying whiskey gets a seat at the table,” says BCS chief of distillery operations Tripp Stimson. So the finishing length must be kept short, and vigilance is definitely required, Stimson adds. BCS’s Cask Finish Series: Amburana was finished for 30–60 days. After the first week, Stimson pulled samples on a nearly daily basis to ensure that the cask influence wasn’t becoming too overbearing.
As with other exotic wood casks, availability is an issue. In 1998, several amburana species were declared threatened by the International Union for Conservation of Nature after native forests were cleared for cattle grazing. After that, Brazil placed restrictions on how amburana could be harvested.
The use of amburana barrels comes at a price: A 53-gallon cask can cost upward of $1,200—nearly five times higher than a new American white oak barrel. Though difficult to tame, amburana lends itself well to different methods of finishing. Some whiskey makers, like Hard Truth and RD1, use amburana inserts or staves rather than complete barrels to finish their whiskeys. Others, like Penelope, double finish using amburana along with other barrels— its popular Cooper Series Rio bourbon is finished using both amburana casks and barrels that previously contained honey. Regardless of how it’s used, amburana contributes very distinct and powerful flavors that are sure to please many whiskey drinkers.
“You can pull the bung out of the barrel, and across the room somebody’s going to know you’re dealing with an amburana barrel,” says Stimson. “The concentration with which you find [the flavors] in amburana wood is unlike anything else.”
5 Amburana Finished Bourbons to Try
94 points - Barrell Cask Finish Series 5 year old, 58.21%, $90
Finished in amburana for 30–60 days Cinnamon, dark-roast coffee, and cocoa powder
92 points - Doc Swinson’s Exploratory Cask Bossa Nova, 56.4%, $80
Finished in amburana for 3–10 days Buttered cinnamon-raisin bagel, cinnamon French toast, and pains aux raisins
92 points - Four Gate 7 year old Majestic Wood Series Amburana Brazilian Oak, 57.55%, $249
Finished in amburana for 35 days Baking spices, snickerdoodle cookies, and white pepper
92 points - Rare Character Single Barrel Series Amburana Cask Finished (Barrel No. AMB-B-09), 57.36%, $100
Finished in amburana for 8 months Cinnamon syrup spice, Mexican hot chocolate, and orange slices
90 points - Starlight Distillery 5 year old Carl T. Huber’s Cigar Batch (2024 Release), 55.85%, $80
Finished in amburana for 3 months Vanilla, cinnamon rolls, gingersnaps, and antique shop oak
