What is finished whiskey? An Exhaustive Guide

Greatly expanded by the craft whiskey movement and bourbon boom, finished whiskey has grown tremendously in popularity, meriting attention from heritage distillers and whiskey connoisseurs.

What is Finished Whiskey?

While almost all whiskey must be aged in oak, finished whiskey refers to the process of taking that aged whiskey and giving it subsequent aging(s) in other barrel(s) or with wooden rod additives. You may hear the first aging referred to as "primary" aging which is typically the longest part of the aging process with the additional aging or "secondary maturation" being a much smaller part of the timeline. 

Finishing Timelines of Common Whiskeys

The following common finished whiskeys and their aging timeline show how much the duration of secondary maturation can vary:

• Maker's Mark 46 - Finished with 10 seared French oak staves for around 6 to 8 weeks
• Angel's Envy Kentucky Straight Bourbon - Finished for 3 to 6 months in port wine barrels
• Dewar's Caribbean Smooth - Finished for about 6 months in rum casks.
• Elijah Craig Toasted Barrel - Finished for 10 months in specially toasted barrels
• Glenmorangie Quinta Ruban - 12 year old whiskey finished for and additional 2 years in port casks

We'll discuss the various types of finish below, but the above shows how the type of wood and format of that wood can change the finishing dramatically. In general, an older whiskey will have more of its own flavor already, so it can better tolerate a longer finishing, but this can still vary widely depending on the strength of the finishing additive.

Why do we Finish whiskey?

Though we know and love the traditional whiskey flavors of vanilla, caramel, corn, and spice, the finishing process can produce new and exciting flavor profiles. When done well, finishing whiskey can add delicious layers of nuance and complexity, improve thickness/mouthfeel, temper alcohol astringency, and provide lovely color. Creating unique expressions can help producers stand out in an already crowded production landscape and give consumers a variety of options, often easy drinking ones. 

The Origins of Finished Whiskey

During the 1800s, merchants trafficking in whisky also commonly traded in wine and other goods. When casks of fortified wine arrived from Spain and Portugal, thrifty traders in Scotland and Ireland would often refill those barrels with whisky to minimize cost. Eventually, those involved came to realize that the sherry and port casks imparted their own unique flavors on the whisky. At the time, this was focused on cost saving and the whisky spent its full lifetime in those barrels. Jump forward to the 1980s, the Balvenie Distillery in Scotland under David Steward tries an experiment, re-casking scotch aged in American Oak for 12 years in Oloroso Sherry Casks for another 9-10 months. The results were a success that we still see on shelves today as the Balvenie's DoubleWood, and they have also produced a variety of other finished whiskies such as the lovely Caribbean Cask, finished in rum barrels. Not to be left behind, Glenmorangie followed shortly with their own Oloroso Sherry finished "1963" and the practice spread to the US over the ensuing decades. 

Common Barrel Finishes

The finishing process is a delicate balance. Flavor changes can happen quickly, and producers must take care that they don't overwhelm the initial whiskey's flavor. Some finishes are dump ready after only a few weeks while most are in the 3 months to 1 year range. There is typically a large amount of trial-and-error as the second cask may perform very differently that those used during primary maturation. Used barrels may finish multiple batches of whiskey and production teams will need to check on these whiskies frequently as the finishing duration required to achieve the same flavor may increase with each use.

• Madeira - Growing in popularity, Madeira is a fortified wine from Portugal's Madeira islands and may have more barrel character due to natural or artificial heat cycling. Madeira may add a silky mouthfeel to the whiskey along with the expected fruit and nut notes while enhancing nay honey sweetness already present. 
• Port - Fortified wine from the grapes of Portugal's Douro region augmented by aguardiente, a neutral grape spirit, that is then cellar aged. Most port is of a red variety and relatively sweet, imparting its ruby color and berry tasting notes to a finished whiskey (often blackberry, cranberry, cherry, and plum to name a few). 
• Rum - Aged rum casks can add some sweetness and reinforce brown sugar flavors. I can usually find a vague banana and some clove, vaguely resemblant of a Hefeweizen. 
• Sherry - A fortified wine consisting of fermented grapes and the addition of a distilled spirit, typically brandy, is one of the oldest and most common of the finishes. Oloroso (nuts, dried fruit, spice, sometimes tobacco), Amontillado (nuttiness, floral notes, herbaceous), and Pedro Ximénez (known as "PX", sweetness, raisins, plums, sweetness, molasses)
• Stout  Beer - Often formerly imperial or other aged stout varieties, these can impart some additional malt, chocolate, or coffee flavors and more substantial mouthfeel.
• Tequila - Ex-Tequila barrels add vegetal notes (read - yes agave) in addition to some citrus. There may also be some earthiness. 
• Toasted Barrel - Potentially the most prevalent finish by volume, especially in bourbon, a toasted barrel finish utilizes a second virgin oak cask that is heated for a lower temperature and longer duration

Compared with other finishing techniques, cask finishing provides a gradual, controlled flavor infusion effect though it adds significant cost and complexity due to having to source, transport, and warehouse all of the extra barrels. 

Finishing Staves/Rods/Spirals

Aside from reusing cooperage, producers are increasingly experimenting with finishing staves, long thin rods of wood that are added to the original whiskey cask. They are often made from various exotic woods including those whose porosity or other characteristics make them ineligible use in barrel construction. Sometimes the staves are simply differently charred white oak. 

• Acacia - Acacia wood staves might contribute floral and honey notes, with a lighter touch compared to oak, potentially adding a delicate sweetness and complexity to whiskey.
• Cherry Wood - Cherry Wood - Cherry staves might add a subtle fruitiness, reminiscent of cherry or other red fruits, with a slight sweetness that can enhance the whiskey's fruit notes or balance out its tannins.
• French Oak - Producers may use French oak staves to get more vanilla and caramel sweetness. Typically the French Oak will be toasted or heavily charred. 
• Maple - Though not as common, Maple wood staves can introduce a sweet, syrupy note to whiskey, potentially enhancing any existing maple or honey flavors, providing a rounder, smoother mouthfeel.
• Mizunara (Japanese Oak) - Growing in popularity, Mizunara is known for its exotic flavors like sandalwood, coconut, and sometimes a hint of incense. 

Finishing staves are often more economical and space efficient compared to cask finishes and have an accelerated finishing process due to the increased surface area exposed to the whiskey. Producers do have to take care that the flavoring impacts do not become too pronounced.

Labeling of Finished Whiskey

Many are surprised to learn that finished whiskey typically no longer qualifies as "straight whiskey" according to the TTB. Straight whiskey can only be aged in charred new oak containers, so the addition of any finish that is used cooperage is enough to disqualify a spirit. Toasted barrels may still qualify as straight whiskey if the toasted barrel is new oak as we see with Woodford Double Oaked and Elijah Craig Toasted Barrel. Age is also interesting as producers can only count the initial barrel aging, though labels like " 7 Year Straight Bourbon Whiskey finished in Oloroso Sherry Wine Cask" are permissible. 

Prolific Finished Whiskey Brands 

In addition to the Balvenie and Glenmorangie, a large number of producers commonly finish whiskies these days, including a number of NDP brands. Most craft producers and scotch distillers will release finished special editions but these brands have finished product on the market at all times.

• Angel's Envy - Port Finish, Rum Finish, Triple Oak, Oloroso Sherry, Madiera, Ice Cider, Tawny Finish, and more
• Barrell - Double Barrel, Mizunara, Rum Cask, PX Sherry, Martinique rhum and apricot brandy, and a medley of special releases. 
• Bardstown - Both their collaboration and Discovery series releases will include finished products like their Amrut rye whiskey, Plantation Rum, Silver Oak Cabernet, Blackberry Farm Oxheart Stout, and a growing number of others
• 13th Colony - Southern Bourbon(toasted maple), Southern Rye (French oak Spirals), Cask Strength Double Oaked
• Dewar's - Caribbean Smooth Rum Cask Finish, Japanese Smooth Mizunara Oak Cask Finish, Portuguese Smooth Port Cask Finish, French Smooth Apple Spirit (Calvados) Cask Finish, Double Double Cask, and others
• Heaven Hill - Basil Hayden Toasted, Elijah Craig Toasted Barrel, Parker's Heritage 12th Edition
• The Macallan - Double Cask (Sherry and Bourbon), Harmony Collection (various cask finishes like sherry, rum, and more), Edition Series (with various cask finishes), and more.
• Penelope - Rosé Cask, Valencia Vino de Naranja, Hungarian Tokahi Wine Cask, Rio Amburana, and many more

The next time you're looking to try something new, pick up a finished whiskey!