Rarest Malts: Glen Isla, Craigduff, Glen Craig, and Mosstowie

Following my recent article on big batch mass-production Aldi whisky, I thought I would turn my thoughts to the rarer whiskies. Closed distilleries are popular because there will no longer be any whisky from these rare beasts, other than those – such as Rosebank and Brora -, which have been restarted. We wait to see how the remaining old casks and new output will be marketed in future years.

Other closed distilleries such as Port Ellen have legendary status, whilst Hillside and Lochside remain niche purchases of mixed quality. Despite steadily rising prices for these collectable whiskies, in many ways they are not rare. There are lots of examples of the aforementioned distilleries circulating in the auction market, and fewer of these bottles exchange hands at prices that allow them to be opened.

There are distilleries with tiny outputs which remain remarkably rare; in Tasmania the Small Concern distillery (aka Cradle Mountain) has been re-opened, but original whisky from the old distillery is exceedingly rare. Nearby Lark distillery has a tiny output and occasional releases in the UK are unbelievably expensive.

Closer to home, Chain Pier distillery was already closed before a handful of casks were released, the distillery having been set up briefly as an experimental distillery to hone the style of whisky to be made at the commercially sized Bonnington distillery owned by Crabbies, parent company Halewood Artisanal Spirits.

The future of the original Dornoch Distillery is unclear, with the announcement this week that the Thompson Brothers have secured planning permission for a commercial sized operation in the town. Eden Mill produced for a few years before moving to a much larger site, with larger stills, resulting in (it’s expected) a similar but different malt flavour profile. The only single cask releases being the hip-flask series of 20cl bottles, some of which, command significant prices at auction.

More niche and potentially rarer still are the experimental malts produced on a small scale for a handful of years at better-known distilleries. These experiments that occurred during the 1970s involved innovations as varied as new still designs and distilling peaty water. One of these experiments resulted in only six known releases.

Photo: The Lomond Still at Scapa

Hiram Walker, a Canadian distillery company, grew into a huge global spirits powerhouse by the 1950s, due to medicinal alcohol production during the Prohibition era. They were responsible for the development of the Lomond still that is behind many of these experimental whiskies as it was a Hiram engineer, Alistair Cunningham, who is credited with inventing the still in 1955. Within these stills there were three rectifying plates that could be dry or water cooled, and could be vertical or horizontal, to greatly influence the type of spirit made. Hiram Walker used them at their Dumbarton Distillery complex, Glenburgie, and Miltonduff.

Seagram’s was a modestly sized Canadian distiller founded in 1830 that grew steadily until the 1920’s Prohibition, which DLC used to sell whisky into Canada legally during prohibition, which was then bootlegged into the US. This highly profitable arrangement allowed for a global expansion to become one of the largest distillers in the world.

Here we are 100 years later, sampling the unintended ripple effect of those temperance rules in a global spirits blog. Certainly, some chaos theory at work here.

Photo: Glen Keith Distillery

Glen Isla

Seagrams converted a meal-mill to create Glen Keith distillery in 1957. It was designed as a “blending factory” to produce a multitude of different styles of whisky, ranging from triple distillation to use of other grains such as wheat. Whilst Glen Keith has remained fairly obscure over the years, it has become of more interest in the last five years, and probably a distillery worthy of some attention from Malt.

The Glenisla spirit – distilled at Glen Keith – is named after the nearby River Isla. This production may have carried on for a number of years, but the only Whiskybase entries are from Signatory Vintage from 1977, which suggests a small parcel was sold to them at some point, with the rest being blended away.

Even at a recent whisky tasting with some seasoned experts and renowned amateur enthusiasts, nobody could agree on the exact production method, but peated water has been used to impart a peat flavour to this malt (rather than smoking the barley). It would appear that the most likely explanation is that water was being smoked in Stornoway and then distilled to make a heavily peated concentrate. This was then transported and added to the unpeated mash about 10 litres at a time and stewed, before going into the washbacks prior to distillation.

It was also suggested that the local Stornoway loch water itself was sufficiently peaty that it simply required concentrating without additional smoking, however it’s unclear then where the smoky notes would come from. Other accounts describe the concentration process as occurring in Glen Keith itself, but the economic value of this supply chain is extremely difficult to understand.

Signatory Vintage Glenisla 1977 36 Years Old – Review

Cask number 19603; hogshead. 43.3% ABV. Roughly £250 to £350 at auction.
Colour: Pale straw.
On the nose: Gentle fruity nose, soft malt, a hint of popcorn, very soft smoke. The fruit is soft oxidised orchard fruit, musty dunnage, dusty vanilla. The peat is adding a depth and richness; a little spice and liquorice develop too.
In the mouth: Sweet and smoky, settling in to soft tropical fruit, floral drops, tinned tropical “travel sweets” in powdered sugar. Pineapple, mango, guava, soft vanilla cream; cask wood spices build gradually with an effervescent fruitiness. The finish is sot and abrupt with pleasant peach, honeydew melon, and gentle wafts of smoke.


Considering this experimental whisky was never expected to reach the market as a single cask – let along age quietly to a ripe age of 36 years – it’s really quite good. The low ABV and softness of all the flavour notes require some significant attention to make the most of them, but the fruit and juicy nature deserve a score of…

Score: 6/10

Only six casks of Craigduff have been released; again, this is probably courtesy of a single parcel sold to Signatory Vintage. It’s almost impossible to definitively confirm which distillery this particular spirit was produced at. Chivas states it’s from Strathisla (the neighbouring distillery to Glen Keith) whereas Signatory Vintage – the bottler of all of these expressions – says it’s Glen Keith.

With this expression, it was both peated malt and peated water that went into the washbacks. This would be in line with Glen Keith being the origin, as it was already importing peated malt for peated Glen Keith (traditionally made on the pot stills) and the peated water used for the Glenisla, so a combination is natural at the deliberately experimental distillery. It’s not explicitly stated that the Lomond Stills were used for this expression, but it is assumed. It was suggested in one source, without evidence, that this was only produced for a few weeks a year before cleaning of the stills, which might suggest that the total outturn was particularly limited. However, the reliability of information on these releases is generally quite limited.

Signatory Vintage Craigduff 1973 36 Years Old – Review

Cask 2517, refill Sherry. 43% ABV. Expect to pay £300 to £500 at auction.

Colour: Pale straw.

On the nose: Petrol lawn mower, smoked octopus, mace, and sweet eucalyptus, fresh mint, plug flesh and sponge cake crust, brown butter, smoked rum and raisin ice cream, paraffin wax.

In the mouth: Quite thin, sweet, with an unnatural chemical note. Cheap hand soap, fruit essence; the peat brings more authenticity and some richness, but it falls away quickly giving a bitter, dry, tannic note on the finish.


There are layers of flavour here, but nothing delicious, and some notes are quite jarring. The presence of the sherry is very limited.

Score: 4/10


Distilled at Hiram Walker’s Glenburgie on a pair of Lomond Stills, Glencraig was named after Wille Craig, the company’s production director at the time. The Lomond Stills were installed here in 1958 and removed at the beginning of the 1980s. There is a lot more of this around, with bottlings from Cadenheads, Gordon & MacPhail, and Duncan Taylor, to name a few. It appears to have been distilled continuously between 1958 and 1981.

Signatory Vintage Glencraig 1976 36 Years Old – Review

Cask 4258, bourbon barrel. 47.1% ABV. Around £300 to £400 at auction.

Colour: Pale straw.

On the nose: Sooty fruit, solvent like alcohol, prickly spirit, oxidised ripe fruit in the background, crisp malt, sweet pastry, gorse flowers, almond essence, toasted coconut, stem ginger biscuits, slightly buttery.

In the mouth: Quite a big arrival of effervescent oxidised white orchard fruits, tongue coating wood spice and a slightly oily sootiness. The balance of juicy fruit, smoky peat, and cask spices gives a richness, and the spirit has a good weight.


Very nice, but not exciting returning a second and third time to this dram, the balance is good, the cask kind.

Score: 5/10


Another Hiram Walker distillery, Miltonduff, had Lomond Stills installed later in 1964. The stills were cannibalised in 1985 to become part of new traditional stills. During that time, the spirit from the stills was known as Mosstowie. It appears to have followed the same recipe and run through the Lomond Stills, however there is a suggestion there is peat in this expression too. I would suggest this must include peated malt. Again, the production appears to have been consistent over the 17 years of production, compared with similarly availability to Glencraig produced for 23 years.

Signatory Vintage Mosstowie 1979 36 Years Old – Review

Cask 25758, bourbon barrel. 46.8% ABV. Expect £300 to £400 at auction.
Colour: Fresh straw.

On the nose: Peaty, aromatic floral notes, swept hearth, nutty notes of peanut skins, buttered toast, smoked cheese and a prickly peaty spice.

In the mouth: Buttered toast covered in demerara sugar, spearmint, crystalised ginger, coconut and almonds, cracked white peppercorns and a smear of chili oil. It’s got the heaviest texture of all four drams sampled here. The finish is sooty with robust peat spices.


This probably has the most coherent flavour of all four of these experimental drams. Some of the characteristics of other great peated drams of 30+ age, but without the tropical fruit notes that elevate them to greatness.

Score: 6/10

Existing Lomond Stills

The wash still at Scapa distillery began life as a Lomond still, but the plates have been removed and a purifier added. This still is operated much like a traditional still and dates from around 1971, although a Lomond Still may have been on site since before 1971. Recently founded Inchdairne have their interpretation of a Lomond Still. And at Bruichladdich a Lomond Still called “Ugly Betty” is used to make the Botanist Gin. Loch Lomond Distillery itself does not have Lomond Stills; instead its straight necked still is much taller.

CategoriesSingle Malt

Graham is at the consumer end of the whisky world; constantly seeking out a bargains and generally very cautious with his limited budget. An occasional visitor to distilleries and a member of the odd whisky club. He does not collect whiskies but has a few nice ones put away for some future special occasion. He enjoys discussions with the wider whisky community and may resemble the ‘average’ Malt reader.

  1. Mark says:

    Sounds like a fascinating tasting session Graham. Several of these bottles made it to Australia years back but I didn’t have the cash/foresight at the time to pick time up.

    FYI – “At Glen Keith the peating came from peat smoked water which was produced in Stornoway – until the plant there eventually blew up. They then started making a peat smoked water at Glen Keith which was used in the distillery. Some of this was also sent to Japan” (Hugh Thompson, retired distillery manager at Glen Keith & Strathisla)

  2. Graham says:

    Hi Mark, the blowing up of the water peating set up is certainly new information to me. Thanks for sharing.

    It was great to taste liquid history but I wouldn’t necessarily want a whole bottle of any of these.



    1. John says:

      Graham, among these I’ve only tried the Mosstowie. I’m surprised you wouldn’t want a full bottle of this. The Signatory I tried is so oily and the flavors are coherent. I guess we can blame it coming from a single barrel.

      1. Graham says:

        Hi John,

        This is a fair challenge, the Mosstowie in the tasting I was involved in was the favourite for most of the group. In terms of flavour it’s very interesting, but I am also considering value for money vs overall pleasure and therefore this is always a personal decision taking in multiple factors.



        1. John says:

          I get what you mean. But as someone who doesnt buy a lot of bottles anymore, £300 to £400 at auction + 1970s + no longer being produced sounds like a decent enough trifecta.

  3. Greg B. says:

    I read this review out curiosity than anything else since my chances of actually tasting any of these is nil. But I was pleasantly surprised to discover a fascinating story about the history of the places and people who made these whiskies. It amazes me that these casks survived intact for so many years. Well done, and well written. Thank you!

    1. Graham says:

      Thanks Ben, that’s very kind.

      The stories here are most intriguing. I could also recommend the Balvenie Stories podcast and the Liquid Antiquarian on YouTube for some interesting stories of whisky past.

      All the best,


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