Why are there so many oak barrels for sale? It’s because they are the secret ingredient to great bourbon; the mystifying piece of the craft that imparts deep, rich flavour and yet cannot be tamed. Dive in to learn more about bourbon, the craftsmanship of producing it, and the use of wooden barrels to finish it.
What Makes Bourbon ‘Bourbon’?
Just like many other spirits (and food items) in the world, the right to call bourbon ‘Bourbon’ is protected and regulated to ensure that what you’re drinking is what you think you’re drinking.
In the same way that there are traditions, rules, and regulations to producing scotch – it must be distilled in a pot still, be aged in wooden casks, and hail from Scotland – there are traditions, rules, and regulations to producing bourbon.
According to the Federal Standards of Identity for Distilled Spirits (27 CFR 5), there are three main rules when making bourbon:
- It must be made in the United States; not specifically in Kentucky (although most is produced there), but in the USA.
- The fermented mash must contain at least 51% corn – although most producers use between 60 and 80% – the rest is typically rye and/or malted barley.
- And it must, by law, be aged in charred, new oak barrels.
Charred Oak Barrels: The Secret Ingredient to Great Bourbon
It is, in fact, that third rule for making bourbon that is the secret ingredient of great bourbon. Charred oak barrels are what instill the depth of flavour, the aroma, and the richness to what starts out as basically corn mash. And it is the oak used in those barrels that determine the flavour profile of the final product.
White Oak Barrels
Also known as ‘American Oak Barrels’; these barrels are crafted from oak that is grown in America – primarily Iowa, Kentucky, Missouri, Ohio, and Oregon. It’s a strong wood with low permeability and easily bent with steam, making it ideal for barrels that will hold the liquid gold bourbon through to maturity.
It’s the flavours imparted by white oak barrels, though, that makes them highly desirable for bourbon makers. Typically associated with the ’rounder’ flavours of vanilla and coconut, there is a richness to the developed flavour that pares well with the strength of the bourbon. Backed by spicy, cinnamon notes; this oak gives a well balanced approach to completing the process.
French Oak Barrels
There are two main differences between French Oak Barrels and American Oak Barrels. The first is obvious; French Oak Barrels are make from oak produced in France. The second is more subtle but is a result of the first difference – oak grown, and harvested, in France imparts different flavour qualities to the bourbon. Generally the flavour profile when using French Oak Barrels is smoother and more satiny. The tannins present in French Oak are responsible for greater complexity and, what is thought to be, a more sophisticated flavour profile.
So, a bourbon producer will choose either White Oak Barrels or French Oak Barrels depending on the flavours that are desired in the end product. But, it is the charring of these barrels that really releases these elements into the bourbon.
Cooperage: The Ancient Art of Wooden Barrel Making
The Germanic word kūpe, for cask, is the origin of the term we now associate with barrel making; cooperage is an ancient art that is still practiced today and is responsible for all the wooden barrels in both the wine-making and the bourbon industries.
It is, indeed, an artform; the selection and aging of the wood (whether American Oak or French Oak), the preparation of the staves (steaming and bending and forming), the construction of the shape, the placement of the hoops, and the final fitting of the head are all pieces of a jigsaw many centuries in the making.
The final step in the making of most barrels is the charring of the interior. A simple process that changes the very nature of the wood and, ultimately, the relationship between that barrel and the bourbon that will fill it.
Charred Oak Barrels have a slightly greater surface area, as the charring expands the wood and opens it up, allowing more of the liquid bourbon to come into contact with the wood surface. Charring also results in chemical reactions that alter the elements available for infusing into the bourbon; specifically the vanilla-y and spicy components are enhanced resulting in a smoother, richer taste. It also provides some insulation against the tannins that are also present in the original oak, minimizing the undesirable bitter notes.
The char level of a barrel determines the intensity of the effect:
- Level 1 Char – mere 15 seconds of charring means minimal charring and therefore minimal flavour impact.
- Level 2 Char – 30 seconds of charring will see significant flavour enhancement but stops short of what is considered optimal.
- Level 3 Char – 5 more seconds of charring (to a total of 35 seconds) is the most popular choice and is considered the optimal char level for best flavour overall
- Level 4 Char – at 55 seconds there is considerable burn at this level resulting in new compounds that are not always desirable but there are producers who experiment at this level and even higher.
The Craftsmanship of Creating Great Bourbon
Three ingredients, two processes, one charred oak barrel, and time are the secrets to crafting great bourbon.
By law, bourbon must be at least 51% corn mash; traditionally it’s higher than this and is often partnered with rye as a secondary grain. Just like grapes used in wine, the varietal of corn used influences the final product. Some corn varietals are produced only for bourbon production and producers typically have their favourites. Unlike corn that is produced for the table, corn for bourbon is left on the stalk to dry allowing the full development of sugars and other flavour compounds.
Yeast is the second ingredient and is usually a closely guarded secret of the bourbon producer. Each strain imparts differing characteristics and is lovingly tended to ensure longevity and consistency. It is the yeast that converts the corn sugars to alcohol so is a necessary ingredient in the bourbon making process.
The third ingredient is water; the clearer and purer the better. Where water comes from can make a significant difference to the end product. Whether from mountain streams, or deep aquifers, water ‘tastes’ like where is comes from and so is often a source of pride for the distiller as a home grown part of the end product.
It is fermentation and distillation that actually produce what will be bourbon. The conversion of sugars to alcohol by the yeast, and the refinement of that alcohol through the distillation process, are the science-y biological and chemical reactions that result in the liquid gold that has yet to be aged to develop the rich, smooth, flavours that bourbon is known for.
The single use of charred oak barrels is the reason why there are so many used bourbon barrels for sale. Federal standards dictate that bourbon must be aged in only new, charred oak barrels
It is the time spent in these charred oak barrels that imparts the final flavours to the bourbon. Rich, creamy, vanilla notes are developed the longer the bourbon is in contact with the charred interior. In fact, the charring also acts as a natural filter; removing unwanted compounds and bitter notes. Bourbon can be aged for any period of time although it is two years in the barrel that produces ‘straight’ bourbon.
What is the Best Bourbon?
Bourbon is as American as apple pie, and is consumed in all corners of the country, but what are the best bourbons?
W.L. Weller 12 Year – a solid bourbon with the complexity and depth that aging 12 years will bring.
Widow Jane 10 Year – a bourbon that holds its water as the highest element with deep cherry, cream, and toffee notes.
Bookers Uncut and Unfiltered – straight from the barrel; it doesn’t get any more ‘real’ than this.
Jefferson’s Ocean Aged at Sea – a gimmick or innovation? You decide. These barrels have voyaged the world in the holds of ships – being exposed to salty air, differing temperatures, and the sloshing of the sea imparts unique characteristics to this bourbon.