Stills: 3 Wash 3 Spirit
Water Source: Conval Hills
Capacity: 2.9 Million Litres
A Quick Word On Distillation.
Before we go any further, a word on Mortlach's rather complicated distillation process is required. Like several other distilleries such as Ardbeg, Springbank and Talisker, Mortlach's distillation process is not the normal double distillation but is in fact somewhere between double and triple distillation. For Mortlach it is generally accepted to be about 2.7 times, it has been this way since the number of stills was doubled in 1897.
The process is achieved by having six stills, three wash and three spirit, that are not working in conventional pairings but more individually. One of the pairs of stills does produce spirit in a standard wash then spirit double distillation process but the other four are more complicated. The low wines from the other two wash stills are separated into two batches, one large batch that is around the first 80% of the low wines and one smaller batch, the final 20%. The large batch (80%) is distilled a second time in the middle spirit still which produces another standard double distilled new make, although it is slightly different from the new make from the first separate pair of stills.
This last 20%, which is effectively the feints of the two wash distillations and as such is quite weak and impure, is sent for its second distillation in the final spirit still which is a smaller one known fondly at Mortlach as 'the wee witchie'. Here the feints of the wash are distilled three times. Only on the third distillation when the spirit has been concentrated and purified sufficiently are any cuts taken and new make is separated out. The foreshots and feints of the final 'wee witchie' run are mixed in with the next batch of 20% low wines.
All these various distillations are cooled through traditional worm tubs rather than the more modern shell condensers. Condensers are filled with many small copper tubes that provide concentrated copper contact, thereby lightening the cooling vapor even further. Worm tubs are hollow spiraling copper tubes housed inside a large vat of cold water. This old style method of cooling provides less copper contact at the cooling stage and therefore helps the spirit to retain more of its oily texture and heavier flavour compounds. It is a credit to Mortlach that they have stuck with this cooling process through the years rather than change to condensers.
This process produces three distinct and separate new make distillates. All three are mixed together in order to produce Mortlach new make before being filled into casks. This process is incredibly important in understanding Mortlach's natural character. While the flavour has evolved to quite an extent over the decades (as we will see shortly), there is an eternal oiliness about Mortlach's spirit, it has always been a robust and meaty distillate and this staggered distillation process with its old school cooling method is centrally responsible for these characteristics.
1930s-1964: An Oily Old Speysider
In 1964 Mortlach underwent a massive and complete rebuilding process that gutted and replaced the majority of the internal equipment and machinery. Although the stills and distillation regime were retained the rebuilding signaled a change in the distilleries character and move towards a more modern style of Mortlach. This makes it easy for us to distinguish between the two eras or production.
Prior to 1964 Mortlach was a very old school, heavy style of malt of which, thankfully there are many bottled examples. The best of these old Mortlachs come from the late 1930s and the years during and shortly after the second world war. The best are inevitably aged versions from Gordon & MacPhail. These are dense, phenolic and elegant drams of staggeringly good quality, they show all the typical characters of whisky form this era, restrained peat, cocoanut, exotic fruits, honey, rancio, tobacco, leather, menthol and a bewildering array of further complexities. There have been examples bottled from 30 all the way up the recent record making 70yo.
Examples from the 1950s and early 60s are less smoky or peaty but show just as much richness, spice, fruit and wax with some striking vegetal and mineral qualities. G&M are again the main bottlers to look out for although there are also some fantastic examples by Cadenhead's as well.
1964-Present: Meat, Fruit and Oil.
Although the refitting of Mortlach was a big deal, changes in the character of the distillate was more greatly affected by the decommissioning of the malt floors in 1968 and, to greater extent, by the converting of the stills from direct firing to internal steam heating in 1971. These changes robbed the spirit of some of it waxy and intensely fruity old style aspects. However the spirit remains to this day a very big, oily and meaty style of distillate. This is evident in the majority of bottlings that have arisen since the changes.
Examples of aged Mortlach are still fairly numerous, thanks again to G&M but also to some great official examples like the Rare Malts bottlings and, best of all, a fantastic 1971 32yo that was a thick, herbaceous, fruity and complex belter of a Mortlach.
These days there are many bottlings from the eighties through the nineties. These are often quite biscuity and occasionally dirty whiskies, a trait that is often accentuated by sherry casks, to either the delight or disgust of the drinker. Mortlach has a naturally gunpowedery dirty quality about it that can be very beautiful but an equally dirty sherry cask can send it into overkill territories. However a clean top notch sherry cask is the perfect vessel for Mortlach's oily muscularity.
Bottlings of Mortlach don't show any sign of slowing down and it is still a fine spirit so hopefully there will be many more great bottlings to be had in the coming years.