By: Scott Ritenbaugh
Bourbon barrels and the interaction between the oak and the whiskey is one of the most interesting elements of the whiskey production process. The same is true for wood-fired barbecue.
The quality of the wood used for bourbon barrels is a very important component because the new spirit will gain character and color from that wood.
The quality of the wood you select for your backyard barbecue also has a major influence on the flavor of your cook.
Impact of Oak Growth Rate – Slower is Better: It is a known fact that the longer a tree ages the more character you get out of the wood, especially vanillas and wood lactones. Once the wood is cut, the method used to season (dry) the wood has a major impact. The wood must be dried before being used to make bourbon barrels – the drying process converts chemical compounds in the wood to more desirable types. How the wood is dried and for how long also has an impact on the quality of the spirit.
It’s accepted industry-wide that air seasoning is better than kiln drying (it reduces tannins and astringency as well as releases more vanillin). Unfortunately, due to a higher demand for bourbon, more and more bourbon barrels are made from wood which has been kiln dried in a matter of weeks as compared to air seasoning which can take a year or longer.
Just like in bourbon barrels, using wood that’s aged naturally outdoors for six months to a year is the preferred method for barbecue. A freshly cut piece of wood, also known as green wood, has too much internal moisture, which will produce more smoke as the wood burns and slow down the combustion process. Furthermore, wood that’s been cured or seasoned in an oven or kiln is a lesser quality choice. The exposure to high heat makes the wood extra dry, which causes it to burn faster and lose flavor.
Why is oak the primary choice for bourbon barrels as well as a popular choice for barbecue?
The reason that Oak is utilized is its unique physical and chemical nature. Oak has the strength physically, its wide radial rays give strength when shaped for a barrel.
Oak is also a “pure wood” as compared to, for example, softwoods like spruce, pine, or fir which contain resins that can pass strong, undesirable flavors to maturing whiskey. When it comes to barbecue, you never should use these softwoods because of those higher amounts of resin and oils that produce thick, acrid smoke when lit. Cook with hardwoods only.
Whiskey barrels made from oak have three broad effects on the spirit:
As an additive – It adds to the taste and aroma of the spirit by providing desirable elements from the barrel. For example vanillin, oak lactone (coconut, bourbon character), toastiness, wood sugars, and color.
As an agent – that removes undesirable elements from new make spirit. For example sulfur compounds and immaturity.
Oak barrels also interact with the spirit. It adds extractive wood elements from the barrel and converts them to desirable elements.
Much like bourbon barrels, one of the more popular selections of wood for barbecue is white oak sometimes referred to as post oak. If you use white oak or post oak for barbecue, you’ll notice the smoke imparts to the meat a slightly sweet, vanilla-like flavor that is very similar to a Kentucky Bourbon. These flavors lend themselves extremely well to the world of barbecue.
Three other kinds of wood that are commonly used in barbecue are hickory, pecan, and mesquite.
Hickory is one of the more popular choices for longer cooks. Like oak, it burns clean but has a slightly stronger flavor that’s comparable to bacon.
Pecan has a mild, sweet flavor when compared to hickory & mesquite.
Mesquite burns hot and fast, produces lots of smoke, and has an intense, earthy flavor.
Other woods that are popular in certain regions for barbecue are Alder and fruit trees such as Apple, Cherry, Peach, and Pear
Alder Abundant in the Pacific Northwest, alder produces delicate, sweet smoke that pairs well with poultry and fish, especially salmon, which is often grilled on alder planks.
Apple, Cherry, Peach, and Pear Similar to pecan, these fruitwoods burn faster than oak and hickory and produce smoke with an extremely subtle and well-rounded sweetness.
But it’s not just the wood itself, it’s the transformation that happens to the wood as a result of the seasoning and heating treatments during the coopering process (for bourbon barrels) that result in the production of pleasant-tasting wood lactones.
The Importance of Heat: The application of heat is an integral part of the process of making a barrel, In order to bend the staves, they need to be heated. The straight staves are arranged inside a metal hoop and slowly heated, typically using steam. As they are heated they become more pliable and are shaped using hoops of various diameters which are added to each end. Each hoop is held in place by the pressure exerted by the staves as they try to straighten themselves. The barrels are then toasted using a form of indirect radiant heat, which caramelizes the wood sugars.
Once the barrels, are formed and have been toasted to the distiller’s specifications, they are then charred – the inside of the barrel is set on fire for a short period of time, which creates a black charred layer.
There are various levels of charring which will have different effects on the flavors the oak will add to the maturing spirit: more vanillins, lactones, “toastiness,” spice characters, and tannins.
Charring barrels causes further transformation. Char removes sulphuric compounds and immature characteristics from new make spirit. Bourbon barrels are typically charred for 40 seconds to 1 minute, but each distillery has their own preferred length of char time. The result of charring is dramatic changes on the surface – for example, wood sugars are caramelized, which will work their way into the maturing spirit.
For barbecue, wood produces its best, cleanest smoke after it fully combusts and catches flame at temperatures in excess of 600ºF. As the wood combusts, it burns off moisture, gases, and oil-soluble chemicals in the wood, eventually reaching the point where the majority of the smoke is water vapor. As that vapor moves through the smoker, it settles on the surface of the meat and then evaporates, leaving behind traces of compounds from the smoke, which give barbecue its flavor and aroma.
Timeline of a Bourbon Barrel: There several milestones that a bourbon barrel and the spirit inside go through over the years of aging inside a rickhouse
0-4 Years – The bourbon will take on the majority of its amber color and some smoky/woody flavors.
5-10 Years – The bourbon will get slightly darker in color and start to pull out the sugars in the wood, adding sweetness to the bourbon. It will start to pull out compounds in the wood that will come across as fruity, candy, and nutty notes.
10+ Years – The bourbon may take on slightly more color and the grainy, sweet, herbal, and fruity notes start to fade away due to oxidation in the barrel. After 12 or 15 years, bourbon can lose some of its complexity and can come across as very smooth and woody. The longer a bourbon is allowed to age, the greater this impact.
The environment (temperature, humidity, seasonal changes) in which a barrel is stored has a significant impact on what the barrel imparts into the bourbon. The same is true for how wood is stored for your barbecue pit. How long the wood takes to dry out will depend on climate. During a dry, hot summer the wood could be ready to go in a matter of weeks if it gets enough sunlight; during a cold, wet winter it may take months—or even a year!
As you can see, Bourbon & Barbecue are linked together by the magic of wood, smoke and char, and that’s why they make such a great pairing. Cheers! 🥃 🥩