April 2024

WHY WE’RE EXCITED ABOUT A RARE CASK THAT LEAKED ¾ OF ITS CONTENTS

“Losing the majority of a cask’s spirit through leakage is rare and not something we want to happen too often, but the whisky that was left in this particular cask blew the team away. This whisky has given us some insights into the effects of oxidation and what the future holds for the casks in our warehouse, and that’s what we’re really excited about.”

Max Vaughan, Founder

“As soon as we discovered the cask in the upper dunnage, we knew we had to try it. Within the hour we were sat around the tasting room table with a couple of glasses. It was clear from the nose alone this cask was different. With assertive notes of ‘rancio’, presenting themselves as pleasant musty and savoury notes, reminiscent of mushrooms and forest floor, it was giving off the personality of a much, much older dram, all balanced by a rich, sweet, and smoky backbone.”

Tom Lindsay Whisky, Ambassador

Wire Works Silver Linings | 61.9% ABV | 89 Bottles | £125

A Leaking Cask 

Back in 2019, we laid down 48 casks with alternative cut points in the Upper Dunnage, our smallest and warmest warehouse space at the Distillery. These particular casks contain spirit from a limited 3-month campaign where we adjusted the distillers’ cut points, essentially later in the spirit run, which captured the light peat from our regular mash bill in a different way, and also elevated tropical fruit notes.

Wind forward 4 years when we were selecting casks for Wire Works Alter Ego (2023 Spirits Business Masters Medal), and we made an alarming discovery (initially at least). As we moved this one particular cask from the dunnage, it was immediately evident that the cask was a little on ‘the light side’ – in fact from a 225L fill, only 58 litres remained!!!

Angels Share, Oxidation and Influence on Flavour

Evaporative losses (the ‘Angels’ share’) over time lower the volume of liquid in the cask (increasing its headspace), with air finding a route through the pores in the wood to maintain an equilibrium of pressure. This oxygen-rich air then gets to work, slowly oxidising the contents of the cask. The oxygen will dissolve into the liquid and start to interact with the compounds within, bonding and becoming part of new, larger and more complex compounds, or breaking them down into smaller molecules.

In terms of flavour, these new compounds add complexity and can exude a range of flavours, from exotic fruits, to floral, or even pleasant musty/nutty/earthy notes (rancio). Rancio describes the complex oxidative-driven flavours that typically develop when sufficient fatty acids, ketones and esters are present (all of which are produced during fermentation, distillation and maturation) and are given enough time.

Note, not all air enters the cask into the ‘headspace’, but can also go through the pores and wood joins that are in direct contact with the aging spirit, however it is believed this ‘route’ into the cask has less of an impact.

Tasting Notes

Nose: Burnt sugar, tree bark, mushrooms, roasted chestnuts, prune juice, bay leaf.

Palate: Bonfire toffee, orange sherbet, clove oil, dark chocolate, dolly mixture candy,    lavender.

Finish: Treacle tart, chilli chocolate, candied ginger.

Available from the distillery shop from Saturday 27th April at 10am

Why Do Casks Leak

Casks can leak (beyond the customary, expected ‘Angels’ Share’ – approx. 2% pa in the UK) for several reasons. Flaws in the wood structure, gaps between staves and temperature, humidity and pressure variances in the warehouse that cause seasonal contraction and expansion in the cask.  Cask imperfections that may be present when the wood is relatively ‘dry’ i.e. before filling, are often addressed naturally once the spirit is added, as the wood swells and closes many gaps.  However, sometimes it’s not possible to detect leaks as they can be small and as the spirit emerges it evaporates quickly, particularly during the warmer months. Sourcing quality casks from reputable cooperages is a key focus for us, and our experience is that excessive leaks are very rare.