Blending spirits is an expertise that may seem like the perfect and intimidating combination of high art and skill that master blenders spend years honing, with results likely impossible to emulate as a newcomer. But it’s not a practice that need be limited to the context of large distilleries. Creating and developing in-house blends of cask-conditioned and finished spirits, using bottles of spirit you already have on hand, is a great way to explore and elevate the spirits you and your patrons enjoy at your bar or home. It’s also a great way to repurpose almost-emptied or less-than-stellar bottles of spirits from your collection, or even portions of occasional misfired distilling experiments that may posess some distant merit. Such a blend is a dynamic thing: A blend of whiskeys — or whatever spirit — cultivated over time, as individual as the person behind it.

You can start with a blank canvas, using a whiskey you’re already particularly fond of. Or perhaps you’re fortunate enough to have a number of bottles running low to combine as a starting point. How the blend develops is then a matter of experimentation and personal choice: It can be created with a specific flavor profile in mind, or could be less empirical in style, comprising a little of every whiskey in a collection.

Storing an in-house blend

Recent years have seen plentiful discussion on the use of “infinity bottles” or decanters to produce and store such in-house blends. For example, read the superb article by Matt Evans at ( quoting master blenders in Scotland including Rachel Barrie (BenRiach, GlenDronach), Sandy Hyslop (Chivas Brothers) and Kirsteen Campbell (Famous Grouse, Cutty Sark). You can take experimentation such as this even further by creating your own in-house cask blends.

This idea is far from new. In Notes on a Cellar-Book, first published in 1920, George Saintsbury documents the wide range of wine and spirits that he had encountered and savored over the years, accompanied by a lively commentary that gives it both a charm and readability. It’s particularly interesting as a historical reference for how people drank and approached spirits. In his section on whiskey, he notes that it “hardly improves at all” in bottles and proposes an alternative system:

The more excellent way — formerly practised by all persons of some sense and some means north of the Tweed — is to establish a cask of whatever size your purse and your cellar will admit, from a butt to an “octave” (14 gallons), or an “anker” (10 gallons), or even less; fill it up with good and drinkable whisky from six to eight years old, stand it up on end, take it half-way down or even a little higher, and, when you get to or near the tap, fill it up again with whisky fit to drink, but not too old. You thus establish what is called in the case of sherry a “solera,” in which the constantly aging character of the old constituents doctors the new accessions, and in which these in turn freshen and strengthen the old.

The use of a cask, rather than glass, allows the spirit to breathe as its flavors marry together, which is why it works so well in this context.

Saintsbury details the solera style of refilling a cask without ever fully emptying it. A number of different casks of different types, styles and sizes can also be kept, with the spirit exchanged from one to another.

Curating character

You can purchase small casks easily online, with sizes down to 1 liter, which means you can experiment without risking a lot of spirit. Small casks also impart their flavor more rapidly than larger ones, reducing the time investment required.

New wood casks will need to be conditioned, both to allow the wood to expand to avoid leakages and to remove the initial raw wood flavor that might otherwise overpower the spirit. A good place to start would be to hydrate the cask by filling it with water and letting it sit a few hours, allowing the wood to soak and swell the joints tight. Check with the cask supplier for advice on best practices for initial conditioning of new vessels.

After this, ambitious in-house blenders can create different cask finishes by next filling the cask with traditional products like port, sherry or bourbon. After a brief while, the contents should be removed — to be consumed or disposed of if they’ve become unpalatable in giving their best to the cask — before the base of the in-house blend is added. A port finish will add a distinctive, rich fruitiness to whatever is next aged in the cask after it, whereas sherry adds a more tart fruitiness with, depending upon the choice of sherry, notes of grape, apple, raisin or nuts.

In a similar fashion, you can try more experimental finishes that wouldn’t necessarily be easy to find on a commercial scale, for example by using wines such as Champagne, or even non-liquids like coffee beans. These investigations will provide interesting and peculiar lessons — for example, storing sparkling wine in a cask is an excellent way to reduce its effervescence, while also leaving a lightly acidic, tart fruitiness to any spirit that follows it into the cask. And although coffee beans can be tricky to empty out, they very quickly leave a distinctive and powerful flavor that can work particularly well alongside heavier-flavored spirits like port.


Once the cask is prepared, first through hydration and then addition of any finishing influences desired, it is ready to fill with the designated spirit. It’s best to have a general plan for the start of the blend — know at least the type and style of spirit to be used as the base. It can then be compounded upon as appropriate, whether that be, like Saintsbury, by adding a single spirit and then waiting until it reaches a specific fill level, or by combining and adding spirits to contribute particular notes.

Be wary of adding any spirits with powerful flavor profiles, like peated whiskeys. Even a tiny volume of these can easily overpower the blend. It’s much easier to add small amounts gradually to achieve the desired flavor profile than it is to wait for a strong flavor to leave the cask.

In-house cask blending is a great way to use up the final drops of a nearly empty bottle, ensuring the spirit lives on in the blend. It is also the perfect use for spirits that, on their own, might have been a tad underwhelming, but could contribute something to a blend. However, do not hesitate to exclude poor spirits — the final flavor profile should be greater than the sum of its parts, not a compromise.

Monitoring the spirit

It’s worth noting a few points regarding the practicalities of keeping and monitoring casks. Check on the flavor of the spirit regularly — the flavor profile will change over time and, if left for too long, the wood or finish may have too strong an influence.

Also be mindful of where the casks are stored. Temperature changes affect how wood affects a spirit — more significant temperature changes will cause the wood to have more of an impact more quickly. You could experiment with storing casks in different environments to explore various effects, or you may prefer to simply keep it in a dark, cool place with a steady temperature.

Another serious consideration is that wooden casks can leak. The author spent a rather stressful hour tidying up the result of a faulty spigot in a cask atop a bookcase and now has a more elaborate system of waterproof trays to stand them in. These trays can hold the casks’ full contents without overflowing, ensuring that, should the worst happen, the spirit will stay safely contained (and not wasted). It is well worth keeping a close eye on casks to ensure any leaks are caught early.

Enjoying the spirit

When the time comes to sample the in-house blend, try taking a small amount from the cask and then letting it rest for a short while — at least an hour or two — in glass, whether that be a bottle or a decanter. Akin to letting wine rest before drinking, this allows the spirit to settle and, in the author’s experience, improves it.

By keeping some of the in-house blend in a decanter, you have a spirit at hand that is complex enough to drink either neat or in a cocktail, an excellent choice for anyone feeling a tad indecisive. A selection of decanters can be found in thrift shops, or old bottles can be used as an alternative. Some of the custom bottles used by spirits producers nowadays are perfect for this purpose, as they have all the ornateness of a decanter, but with a more air-tight cap that will reduce the loss of more volatile notes and aromas.

Over time you can develop a range of in-house blends. Saintsbury mentions having made his own blends of Scotch and Irish whiskies, as well as Holland gin and brandy. The author has casks for bourbon and Cognac, as well as glass soleras (in 2–3 liter bottles) of rye, Armagnac, tequila, Calvados and even baijiu. These have proven to be fantastic ways to explore and experiment with a range of flavor profiles, and they produce unique spirits to share and enjoy with patrons, friends and family.