Single Pot Still Irish Whiskey: A Complete Guide

From a techy point of view, single pot still whiskey is made from a mixed mashbill which legally (more of that later) contains a minimum of 30% malted barley, a minimum of 30% unmalted barley and 5% ‘other grains’ which is distilled in, you guessed it, a pot still. Sometimes twice, most often three times.

Why unmalted barley? From a whiskey-making standpoint because there are sufficient enzymes within the malt to be able to convert the other starches into fermentable sugars. (Irish whiskey also permits the use of enzymes to assist in this). 
It get more interesting when you ask that question from an historical angle. Mixed mashbills started as a matter of expediency in the early 18th century - distillers using whatever surplus grains were available that year - which then evolved into a signature of that producer. Its story is that of Irish whiskey’s - from farm stills to small commercial producers, to an industry.

These early variable mixes began to be standardised as commercial distilleries were established in towns and cities and were then required to produce a consistent flavour of whiskey. 

As well as the base of malt and barley, these early recipes contained a high percentage of oats - sometimes malted - and on occasion wheat. It’s often been written that single pot still began as a form of tax dodge when, in 1785, a malt tax was imposed in Ireland. By using less malt, the theory went, distillers would pay less to the revenue. True enough, but the practise was already well established.

The Rise 

By the start of the 19th century, the Irish whiskey landscape had changed. There were small producers making illicit whiskey (aka poitín) from malted barley, often peated, predominantly in the west of the country, while legal ‘Parliament’ whiskey - aka single pot still - was being distilled in Dublin, Cork, Galway, Limerick and some larger market towns. These were large enterprises and it was this mix of consistent quality, identifiable style at volume which gave Irish whiskey a head start over Scotch. By the 1850s, the most popular whiskey style in Scotland was Irish - be that authentic single pot still, or copies of it made in Scotland). Single pot still became the gold standard of whisky.
The two countries, whose adventures in whisky had been on parallel tracks since the 15th century began to separate. Scotland followed the single malt and grain trail and began to blend, while Ireland stuck to single pot. That’s not to say grain whiskey was rejected in Ireland, but what was made was exported to the UK. 

The seductive richness of single pot still appealed to the emerging middle class drinker who was beginning to move away from rum and brandy. Its weight also meant it was the ideal base for toddies (the mixed drink of the early- to mid-19th century). Although each distiller would have its own mashbill, most followed the principle of a five-grain ‘cascading’, roughly: 30–50% barley, 30–50% malt, 10–22% oats, 4–12% wheat, and 1–4% rye. This five grain mash would be in use until the early 1960s.

Distillers would sell their whiskey to ‘bonders’ (grocers and wine merchants) who would age it in their own casks and blend to their own specification. One of these was Mitchell & Sons of Dublin which bought from John Jameson & Sons’ Bow Street distillery. Mitchell’s then aged the whiskey in a variety of casks for different lengths of time. Each would be daubed with a ‘spot’ of coloured paint designated by age and cask type.

The Fall

The whisky world had changed by the end of the 19th century. By then, Scotch blenders had perfected their craft and were exporting globally at volume. Significantly, they also had adjusted their recipes to suit a consumer palate which preferred lighter style of whisky served as a Highball. 

Ireland’s pot still distillers saw no need to change. Sales began to slip. All whisky was battered by economics, war and taxation in the early 20th century. Ireland also had to cope with the loss of the Empire market when it gained independence in 1921. The combination of the Great Depression, high domestic high taxes, an export ban and a reluctance to deal with bootleggers saw the Irish industry collapse. 

In 1966, the three remaining distilling firms in the Republic (John Jameson & Sons, Power’s, and Cork Distillers) merged to form Irish Distillers Limited [IDL] with production switched to a new, purpose built distillery in Midleton, Co.Cork.

Single pot still was still made but was used only as an element within blends where its oily, juicy added texture and weight to Power’s Gold Label or Crested Ten. Only two of the old bonders pot stills, Mitchell’s Green Spot and Gilbey’s Redbreast remained. By the 1980s only the former was available. With the change in role came a simplification of the mashbill. Wheat and rye went, while oats were reduced to a walk-on part. In the 1970s they too were removed. Single pot still, the glory of Ireland had slipped into invisibility.

The Rise

The rise of single malt Scotch from the 1990 marked a change in consumers’ perception of whisky. Provenance and a willingness to explore flavour were now the driving force. Time, once more, for single pot. 

In 2005, IDL launched a new range: Green Spot, Redbreast, Midleton Barry Crockett Reserve, and the mighty Power’s John’s Lane but a decade or more would pass before Ireland saw a new generation of distillers beginning to produce.The most enterprising of these began to seek out points of difference. Single malt was an option, but single pot still seduced many of the most enterprising. 

The new Irish industry required a code of practise and in 2014 a Technical File defining whiskey styles was put into law. Because IDL was the sole producer of single pot at the time its recipe, which we saw at the start of the piece, was used. The problem was it restricted everyone to use the same template while ignoring history (including that of IDL itself). 

Protests started - led by distiller Peter Mulryan in Blackwater and historian Fionnán O’Connor who researched the old recipes and, with the help of Drogheda’s Boann distillery, distilled them. These ‘historic mashbills’ were pot still in limbo. Lobbying to change the Technical File has continued, with IDL in support, and it looks likely than a new definition which ups the ‘other grain’ component to a maximum of 30%will be passed.

The Future

The best of the new Irish whiskey-makers are involved in a profound exploration of roots. What is Irish whiskey, what has it been, how can we draw from that, but also make 21st century whiskeys and single pot still is a defining part of their search. Central to this has been the return of oats. Yes, they add creaminess and a dairy-like quality to the whiskey but they also act like a liquid glue, binding barley and malt together as well as generating new aromas. 

There is a wild freedom attached to these new single pots. If you can use oats then why not malt them, or malt and peat them (as see at Killowen and Ardara), what about returning rye to the mix, or reintroduce variations on the old five grain mash [Micil]? Boann keeps one foot in the current legislation while also making ‘non-compliant’ pot still [TWE bottled one for The Whisky Show last year]. All are worth exploring - as are the old stagers. Ireland has regained its whiskey soul.