Worms and whisky
22.06.20 by Tim Foster – Sales Manager, Lindores Abbey Distillery
When making Single Malt Scotch Whisky, each individual part of the process affects the flavour, aroma and texture of the spirit produced.
Subtle differences, distillery to distillery are what create the nuances found in Single Malt Whisky. Each distillery alters each variable to suit their aims and attain that legendary ‘house style’. Be that clear wort, long fermentations, gentle distillation or something as unremarkable as how spirit is condensed, all of which can have a profound effect on the spirit produced.
During distillation we use heat to turn alcohol into a vapour, separating it from the wash and low wines in our pot stills. These vapours rise up and as they whirl and swirl around they come into contact with the copper sides of our stills. With each interaction between vapour and copper, impurities are removed from the spirit. Naturally, the more copper contact there is, the lighter the that spirit is produced.
Separating the vapours is the initial stage in the distillation process, we must also somehow turn the vapour back into a liquid so that it can be contained before racking into cask. And it is here that the often understated condenser comes into the picture.
In times gone by, for arguments sake 500 odd years ago, spirit was produced in clay or glass stills and was condensed through air cooling. Given what we know about the role copper plays in removing impurities from spirits, you might suppose that the spirit produced in 1494 was a little on the harsh side. But that’s not fair as Friar Cor isn’t around to defend himself. That said, it must have been pretty good if the King was ordering it for his parties… erm for medicinal purposes, of course, not parties…
Fast forwards a few hundred years and copper became the material of choice for crafting stills, along with an innovation curiously named a ‘worm tub’. These contraptions extend the lyne arm of the still into a coil which sits immersed in a cold bath of water (most usually outdoors). As the vapour passes through the submerged coil, the hot gasses condense onto the inside of the copper pipe and turn back to a liquid. During the winter months, the vast temperature difference creates optimal conditions for condensate to form. In the warmer months, this isn’t so easy to control. As a result, the spirit produced using worm tub condensers can often be described as having a heavier or even sulphury character.
As with many aspects of Whisky making, the majority of Scottish distilleries including Lindores Abbey Distillery use a more modern ‘shell and tube’ condenser system. Spirit vapour passes through a honeycomb of copper tubes around which cold water is pumped, this method is far more effective at condensing vapour to spirit and therefore tends to produce a lighter spirit character. It’s said that some distilleries which changed over from worm tub to shell and tube systems chose to change back again as their spirit character veered too far from their ‘house style’.
In an industry driven by innovation and sustainability I wonder what technological advances might bring to future Whisky production? I’ll admit to being somewhat torn, on the one hand the romanticism offered by the traditions of Whisky stirs fond emotions. Whereas our responsibility as an industry to ensure we continue to strive for sustainable production, looms heavy also. As with everything, I’m sure there is a balance to be found. The industry has come a long way in 500+ years…
Cask Ownership at Lindores Abbey Distillery
The distillery is of course currently closed but you can still chat to Elliot, our Cask Custodian about our cask ownership scheme and what is involved. We still have a lot of exciting projects going on with different types of casks coming through – but they are all very limited so get in touch if you would like to explore different opportunities within the whisky world. You can contact Elliot on firstname.lastname@example.org or find out more at https://lindoresabbeydistillery.com/welcome-lindores-abbey-distillery/cask-ownership/