Cragganmore, single malt Scotch, Speyside, 12 years old, 40%, $59
Craigellachie, single malt Scotch, Speyside, 13 years old, 46%, $55
Cragganmore and Craigellachie were both established in the late 1800’s (1869 and 1891, respectively), during a booming period of distillery construction and expansion in Speyside which was fueled by the penetration of new railroads into the region. With only 11 miles separating the two distilleries, one could be tempted to call them neighbors, but that might be a bit of a stretch as there are 10 other active distilleries between them, following the course of the River Spey.
While they started off with different owners, Cragganmore was sold in 1923, with the company that owned Craigellachie (partially on its founding, fully by 1916) acquiring a 50% stake. That company had full ownership of Cragganmore by 1966. The common ownership wasn’t always obvious on paper though as the parent company held its many distilleries through a variety of subsidiaries and licensees.
A complicated series of mergers and acquisitions between 1987 and 1997 led to the creation of Diageo, which became the world’s largest producer of spirits. The new company’s whisky holdings were viewed as a monopoly though, so they were forced to sell off the Dewar’s brand along with Craigellachie and three other distilleries. This group package was quickly picked up by Bacardi in 1998.
The 75 year period of shared proprietorship between Cragganmore and Craigellachie is an interesting bit of history, but there’s another commonality between these two distilleries which has prompted me to compare their flagship single malts; worm tubs. This old-style method of cooling the vapors produced by a pot still and re-condensing them back into a liquid is said to add a unique meaty quality to the whisky. While Cragganmore and Craigellachie are both in the minority group of Scottish malt distilleries that continue to use them, every time I read a piece on worm tubs I seem to see a different number stated for the size of that group.
Clearly, I was going to have to roll up my sleeves and put together a comprehensive list of active malt distilleries that continue to employ worm tubs. But first I’ll go over how they work and explore the differences of their more modern counterpart.
The worm part of the equation is just a very long (about 300 feet) copper tube which is fashioned into a coil roughly 10 feet in diameter and 10 feet in height. The tube itself starts with a diameter of about eight inches and gradually tapers down to two inches or so over its length. This whole assembly is submerged in a large vat of cooling water; the tub. The traditional tub is an open-topped wooden vessel. Cold water pours in from the top and sinks due to its greater density. As heat exchanges through the copper coil, the water warms and rises to the top, making its way to the drain which has an opening near the water’s surface. All the while, the vapors moving through the worm are cooled and liquefied.
The shell-and-tube condenser, which is the more modern equivalent of the worm tub, was actually invented in 1825, but its usage didn’t become widespread until the 20th century. This piece of equipment consists of a large number (upwards of 100) of straight copper pipes of relatively small diameter (half an inch or so) all running parallel and arranged in a circular pattern. These pipes are six to ten feet in length, and held in place by passing through a round copper plate at each end. This whole arrangement is contained in a copper shell which is two to three feet in diameter, with capped ends forming chambers that are separated from the center portion by the above mention round plates. Cold water is pumped into the bottom chamber, and forced up through the copper pipes, making its way to the upper chamber and exiting via an outlet pipe. The vapors from the still enter the central cavity, passing through the outer shell near the top of the condenser, but below the upper plate. Surrounding the water filled cooling pipes; the vapors turn back to liquid and fall to the bottom of the center chamber, where they drain out.
The picture below shows the back of the Springbank stillhouse, where you can see two shell-and-tube condensers working alongside a traditional worm tub. Well, it’s mostly traditional; the wooden tub has been updated to a more modern stainless steel version, but rest assured, the worm inside it is still copper. As you can see, the modern condenser takes up much less space. This allows the option of placing the condensers inside the stillhouse, while worm tubs are always located outside. I’m also under the assumption that the more efficient shell and tube condenser can perform the same job with less cooling water.
The important difference between the two types of cooling equipment, in terms of how the whisky will end up tasting, is a matter of copper contact. A worm tub, with its large diameter copper tube, actually puts the vapors in contact with less copper before it condenses. The small diameter of the tubing used in a modern condenser increases the ratio copper surface area to spirit vapor volume. More copper contact equals more refinement and purification of the spirit.
When the gaseous spirit comes in contact with a copper surface, chemical reactions occur and the heavy, undesirable compounds (primarily sulfur based) combine with the copper and precipitate out of the spirit. This happens both in the still and beyond it, during the condensing process . The pictures below show the spirit safe at Springbank, and all of the blue-green stuff you see is copper sulfate that has come out of the spirit.
Getting rid of these sulfur compounds is good, to a certain extent. There’s nothing wrong with producing a very clean spirit, but in the small quantities that are typically left behind by the use of a worm tub, these sulfur compounds can add a rich, meaty, rustic quality to the whisky.
To figure out which distilleries are currently using worm tubs, I took my recently composed list active malt distilleries and did Google image searches of each distillery name along with the terms “worm tub” and “condenser” to get visual confirmation of which method they were using. I then went a step further and did the same for the newest crop of Scottish distillers which have gone online over that last three years.
I came across some interesting bits of information along the way. As mentioned above, Springbank is unique in that it uses a mix of both methods. While traditional wooden tubs can be found at places like Glen Elgin and Talisker, there are several examples of rectangular shaped cast-iron tubs housing the copper worms. This is actually the case at both Cragganmore and Craigellachie. In this type of arrangement the worm can snake back and forth in the tub, or be set up as more of a squared-off coil.
As I searched, I realized that in most cases where shell-and-tube condensers were located outside, they had replaced existing worm tubs without any coinciding structural changes being made to the stillhouse. For newly built distilleries or a reconfigured stillhouse where shell-and tube condensers were being used, they would almost always be located inside. Bunnahabhain has a mix of these two scenarios; the original worm tubs were replaced with outdoor condensers but the second set of stills added at a later date have their condensers located inside the stillhouse. Most distillery tours don’t go out behind the stillhouse, so the condensers located outside are often unseen and infrequently photographed. My search for images of them was quite frustrating at times.
The traditional arrangement for a shell and-tube-condenser is to have it standing vertically, but there are a small number that are oriented horizontally. Glenallachie has all four of its condensers set up this way, while two distilleries employ a combination of both orientations; Dalmore having theirs outdoors, and Macduff with theirs inside the stillhouse. The condensers should work the same either way; these setups are simply dictated by the space that was available when the equipment was installed.
Another interesting example is the Royal Lochnagar distillery, which has worm tubs but runs them at a relatively warm temperature. This is done simply by having a slow inflow rate of the cooling water coming into the tub which has the overall effect of raising the average temperature of the water in the tub. In turn, the spirit takes longer to condense and remains as a vapor much further down into the worm, increasing the amount of copper contact.
Conversely, for a period of time the Dailuaine distillery had stainless steel shell-and-tube condensers connected to two of its six stills. I believe spirit was vatted together from all three sets of stills before being entered into casks, giving an overall effect similar to the use of a worm tub. Following that lead, the relatively new Roseisle distillery has some of its stills connected to two condensers; one copper and one stainless steel. This gives them the flexibility to create different styles of whisky, depending on which condenser they run the spirit through.
Surprisingly, some distilleries have changed the type of condensing equipment they use in recent times. Dalwhinnie went through a period of modernization in 1986 and switched from worm tubs to shell-and-tube condensers. After nine years it was decided that the character of the spirit had changed too much, and the worm tubs returned in 1995. The original tubs had been the rectangular cast-iron type, but the more traditional round wooden style was chosen the second time around, primarily for the visual appeal to visiting whisky tourists. With an even more recent change, Glen Scotia appears to have switched over from worm tubs to shell-and-tube condensers around 2011 or 2012.
Amazingly, 11 new distilleries have begun producing whisky in Scotland since the start of 2012. Only one of those, along with one other recently established (2008) distillery employ traditional worm tubs. I’ll start my list with these new outfits, followed by the other independently owned facilities and then move on to those owned by the big whisky groups.
So, 18 out of 110, or a little over 16% of the distilleries are using worm tubs. As for Craigellachie and Cragganmore, both distilleries spent much of their histories supplying whisky to blenders rather then being bottled as single malt. The first official bottling of Cragganmore was the 12 year old that we still see today, when it became part of the Classic Malts range in 1988. A Port Cask finished Distiller’s Edition followed in 1997, and several limited edition bottlings have appeared since 2000. The first official bottling of Craigellachie was a 14 year old that was part of the Flora and Fauna range for most of the 1990’s. That was replaced by another official 14 year old bottling which was produced between 2004 and 2007. Then, late in 2014 the distillery’s owner finally decided to capitalize on the brand’s single malt potential. They released a full range, which includes the flagship 13 year old, along with a 17 year, a 19 year (travel retail only) and a 21 year. A 31 year old bottling is also in the works and set to be released very soon.
Comparing the two visually they are similar, with a golden/honey yellow color. The Cragganmore does appear to be a touch darker though.
The nose is bright and fragrant, primarily showing tree fruit (pear and apricot) along with some floral notes (lavender?).
The palate is complex, with cereal grains, waxy fruit and a slightly perfumed floral character. Delicate nuttiness and just a subtle whisper of peat smoke add to the complexity.
As it moves through the finish the nuttiness intensifies and spice notes emerge.
Overall, this isn’t a style of single malt that I’ll ever love, but I’ve gotten to a point where I can appreciate it as a good quality whisky in spite of its strong floral notes and my aversion to them.
This one is weightier on the nose, with malty, gingerbread-like grain notes. Its tree fruit aromas stay more in the background, perhaps with a bit of that meaty quality emerging.
On the palate it’s more full bodied. There’s a complex mix of dark, weighty flavors; malt, Demerara sugar (but not in an overtly sweet way), roasted meats and a touch of fruit cake.
The finish starts off with sweeter notes before it evolves into a dry, slightly nutty ending that has much more intense spice notes than the Cragganmore.
Overall, it shows more depth and intensity, and I find it to have better integration, with its various characteristics tied more neatly together. I have to admit that it also has a flavor profile which I’m more agreeable to.
I’m under the impression that the heavier compounds left behind by worm tubs are more susceptible to being stripped out by chill filtration. Part of the difference in character between these two may be down to the fact that the Cragganmore is chill filtered where the Craigellachie is not. Tasting a higher proof, non-chill filtered example of Cragganmore is fairly high on my list of priorities.