Barrel-Aging Spirits


The Beauty of Brown
Many people don’t know that all spirits start out sparkling clear. They don’t know that their favorite amber or golden-brown liquid in a glass started out looking like vodka when it first came off the still. Well, it likely did not taste like vodka (at least we hope not!)

While vodka is a neutral spirit produced at the highest proof possible and then diluted with water; whiskey and rum are produced at lower proof where flavonoids and cogeners (larger molecules that deliver flavors and some aromas) are extracted along with the alcohol. It actually tastes pretty good… just not like the smoother and more interesting stuff that comes out of a barrel after aging for a time.

Good Things Come to Those that Wait… Just Enough Time!
Technically, it only takes a few days to distill a barrel of whisky, but it takes time for valuable contents inside to mature. Although you could drink it straight away, it wouldn’t be the oaky, vanilla, citric, peaty, rich liquor that whiskey fans know and love.

So what transpires in the months, years or even decades that a whiskey is left to age?
Traditionally, whisky is aged in oak barrels that are either toasted or charred when they are built, creating a layer of charcoal that filters out the raw spirit’s unwanted flavors. Through a chemical process called adsorption, the molecules that make young whisky so harsh are drawn to the barrel’s wall, creating a thin layer of everything you don’t want in a drink. At the same time, the wood adds flavor to the whisky, slowly infusing the liquor with lignin and vanillin (for vanilla-like taste), lactones (for a buttery flavor) and tannins or “wood spice” (which makes the whisky dry).

The longer you age, the more the phenols bond with other things in the solution to form new compounds. Examples include: phenylated carboxylic esters, which tend to taste like honey; guaiacol which provides a smokey smell; eugenol that smells of cloves and spice; 2-Methoxy-4-methylphenol that smells of coffee and mushrooms; and syringealdehyde that smells of rose and citrus.

It is Hot and Cold Inside with a Chance of Goodness
Bourbon distillers often age their whisky in dry environments that help it evaporate and concentrate faster than scotch, which is usually aged in humid climates. In general the older the whisky, the more complex the taste and the pricier it is. But, depending on the location and environment in the barrel house, there is a limit where a spirit in a barrel will start to decline with further aging.

There is also the “angels’ share”: the amount of product in the barrel that evaporates over time. Barrels actually breath. As the contents warms, it expands. It penetrated into the wood staves and then exits when the contents cool. Some spirit escapes through the pores of the wood and evaporates. This cycling back and forth between hot and cold accelerates the extraction of flavors from the wood of the barrel, and with more heat there is more evaporation.
The climate in the barrel house also plays a big role in the whisky’s taste: primarily temperature and humidity where the barrel is located. Barrel houses tend to stack barrels… it is generally hotter at the top during the day, and cooler at the top during the night. Translated, this means more cycling for the barrels on top and less for the barrels on the bottom.

Of course the evaporation concentrates the spirit and all of the flavors. A barrel loses 10% of its liquid volume the first year, and 2-4% on average every year after depending on heat and humidity. So that eleven-year old Four Roses Kentucky Bourbon you like so much? It lost 50% of its contents in the barrel before it was bottled.
Lastly there is blending. A blending master can taste the results of several barrels located in different locations within the barrel house, and blend them to create a better and more-complex tasting final product than any single barrel in the blend.

Wrap this Up. I’m Thirsty!
In summary, the brown stuff in the glass that we like so well required a master distiller to make the best clear spirit, and then a master barrel house manager to ensure it was aged to perfection, and then a master blender to make the final magic that goes into the glass.

That is a lot of mastery. Here at Patio29 we will make good stuff, then great stuff and then fantastic stuff. There are no shortcuts to mastering these crafts, but we will never sell a drop of brown spirit that we do not thoroughly enjoy drinking ourselves.


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