A mini guide to Mini Casks

Mini casks. Pretty awesome, huh?

I’ve lost count of the number of times I’ve been asked, either by bar owners or just experiment-loving whisky-geeks, whether we can get hold of little diddy casks for them to mature stuff in.

So, ladies and gents, here we are. Mini casks, each with a diddy little bung to go in the top of the cask. Plus a nice little tap from which to dispense your very own cask-aged products.

The mini casks are made from brand-spanking-new fresh American white oak, which has been given a medium toast level. As with ‘normal’ casks, the ends are un-toasted.

A charred whisky cask

Why mini casks mature spirit quickly

The first thing you need to note about these casks is that they’re intense. The spirit or beer/wine/whatever-your-poison-is will develop inside these casks pretty darned quickly. With *a lot* of oak influence.

The very first day that I received a sample of these, I filled one of the 1-litre ones full of vodka (Smirnoff Black, since you ask). After a couple of months, it looks more like a well-matured bourbon than anything else.

The fact that it matures so quickly is intrinsically linked with the surface area to volume ratio of the cask.

Now bear with me, and I’ll educate bore the socks off you.

#MathsAlert

If we take the internal surface area of your average 225-litre whisky hogshead and lay it out flat, it’s going to be about 1.8 sq/m*.

If you take the internal surface areas of 225 1-litre barrels, you get about 10.8 sq/m*.

This means, therefore, that there’s (proportionally) approximately 6 times more surface area available for the spirit to interact with. And we all know that wood is where most of the flavour comes from in whisky…

This, in turn, means that you’re going to have a spirit that’s got roughly the wood influence of a 2-year-old bourbon (the minimum legal age for a bourbon) inside of two months.

Behold! The mini cask!

A masterclass in mini casks 

Now I know what you’re all thinking. “All my worries are over, I’ll never need to buy any of that ridiculously expensive ‘aged’ whisk(e)y again!”

Whilst there’s no denying that the wood influence happens quickly on this scale, there is genuinely no substitute for time. Wood on its own is not a panacea. There’s a reason the SWA has such a problem with people using additional toasted oak staves to accelerate the maturation rate of a cask.

My 2-month-old spirit was oaky. Very oaky. It’s also sweet, spicy and incredibly vanilla-rich. If you gave this to pretty much anyone, they’d tell you it was a bourbon (I left a bit to evaporate in a glass over a weekend, and it even formed a sticky residue in the bottom of the glass – such is the sugar content of the wood). They’d then probably go on to tell you that it’s pretty overpowering and unsubtle.

Buy your cask today

This said, I have caught myself subconsciously taking several sips throughout writing this post, which is usually a good sign. It’s also worth pointing out that because I used Smirnoff Black in this experiment, the colour is going to be much less intense than if I’d matured some new-make at 63.5% ABV (ethanol is a much more powerful solvent than water, so a higher ABV spirit will extract more from the wood).

We’d therefore recommend that, unless you actively want a product that’s intensely oak-rich, you think about maturing something else in the cask before you go on to cram it full of whatever it is that’s already going through your head… Just a bottle of vodka would do, just something to take the initial oak-hit. Let it fall on the Quercus-Grenade for you.

So – without further ado – fill your boots!

American White Oak Toasted Barrel – 1 Litre**

*This isn’t exactly right, as I’ve used calculations based on spheres, and barrels aren’t perfectly spherical, but you get the idea…

**At the time of writing, we also had stock of Kentucky Toasted Oak Barrel – 5 Litre,20 Litre, and 50 Litre. These have since sold out.