I hashtag #wormtubs all the time on Instagram and wonder if anyone even knows what I’m talking about. I have climbed to the top of multiple hills within Oban to try and get a glance at their small worm-tubs – a true hunter. It seems I have become sort of a “worm tub” seeker and with good reason. My Single Malt Scotch Whisky preferences tend to lean towards whiskies that include a dash of every flavor. A bit of fruit, a dash of spice, malty-nutty qualities, a hint of smoke and maybe even that dreaded word “sulfur”. Although sulfur has become quite a broad term, it is best to take it with a grain of salt. Actually, I don’t mind some salinity in my whisky either.
For me, sulfur means funk. This could present itself as a musty quality, a heavy, old, drank fruit, a few dirty socks or maybe you actually get an eggy taste. Where is this coming from? Sure, there could be something that went awry with the whisky and maybe during maturation but these are tried and true tasting notes of a handful of distilleries in Scotland. Many factors could play a role as well, including fermentation times, size and shape of pot stills, how long you run your distillation, cut points, etc., but it also can be how a distillery condenses that vapor back to a liquid during distillation. See below.
Copper is so important to our whisky production because of three main reasons:
Malleable. This is needed to create the different shapes, boil balls, swan necks etc. that make each distillery’s spirit taste just a bit different and unique.
Heat Conductor. We need these copper kettles to boil up wash and low wines.
Reactive. Copper helps to eliminate sulfur compounds in the distillate.
All of these means, the more copper contact you have in a distillation process, typically, the more delicate and less sulfur forward style of whisky you will make. As you look at the pictures above, imagine a hot vapor rushing into a space of say, about the circumference of you giving someone a big bear hug versus the circumference of a whisky bottle. You will have more, quick, hot and aggressive copper contact with the whisky bottle size than a bear hug. The bear hug represents worm tubs and the whisky bottle would be the shell and tube. As I list the distilleries left with worm tubs below I think you will see a theme although there are some anomalies.
- Glen Elgin
- Old Pulteney
- Royal Lochnagar
- Speyburn *spirit stills connected to worms, wash stills are shell and tube
- Abhainn Dearg
Seek them out if you’d like and if you do, I’ll see you out there on the hunt!