Chapter 11 Production of Scotch and Irish whiskies: their history and ...

Production of Scotch and Irish whiskies: their history and evolution 141distilleries in Scotland, 95 are highland malt whiskydistilleries. Of these, no fewer than 49 are situatedin an area measuring 50 miles east to west and20 miles southwards from the Moray Firth. Thisarea of Speyside has been called the ‘Kingdomof Malt Whisky’ (Cameron Taylor, 1970).Classification of the four whiskies distilled on theislands of Jura, Orkney and Skye is disputed.Some authorities list them along with the Islaywhiskies as ‘island’ whiskies, others as highlandwhiskies, which is geographically correct. Thereare also eight grain whisky distilleries in Scotland.Whiskey distilling in Ireland was, as has beennoted, first recorded in the 12th century. By 1556,it had become sufficiently widespread to warrantlegislation to control it. A statute proclaimed thatyear stated that a license was required tomanufacture the spirit, but that peers, gentlemenowning property worth £10 or more andborough freemen were exempt (McGuire,1973). Taxation of whisky distilling graduallybecame more excessive and collection of taxesbecame increasingly efficient. However, in 1779there was an important change in the distillerylaws. An attempt was made to limit the extent ofevasion of spirit duty by prescribing a minimumrevenue to be exacted from the owner of eachstill. The effect of this legislation was dramatic. In1779, there was said to be 1,152 registered stillsin Ireland. By 1790, this number had fallen to 216and this inevitably fostered widespread illicitdistilling (McGuire, 1973). This legislation lasteduntil 1823 when it was replaced by laws that taxedIrish whiskey on the volume of production,legislation that is essentially still in force today.Development of the Irish whiskey distillingindustry in the present century has inevitably beeninfluenced by economic circumstances and bythe political division of Ireland into the Republicand Northern Ireland that occurred in 1922.Barnard (1887) described visits to 28 distilleriesin Ireland, but closures and amalgamationsfollowed such that when McGuire (1973)prepared his account, there were only twowhiskey-distilling companies in Ireland, one withdistilleries in Dublin and Cork in the Republic andthe other with plants in Bushmills and Colerainein Northern Ireland. These two companies havesince amalgamated and have concentrated theirdistillery operations in Cork and Bushmills. Therehas also been a move towards production of alighter Scotch-type whisky in Ireland to replacethe heavier traditional Irish whiskey.Outline of whisky productionprocessesWhiskies differ basically in the nature andproportion of the cereals used as raw materialsand on the type of still used in the distillationprocess. These differences in the productionprocess are illustrated in the flow diagram inFigure 2 for production of Scotch malt whisky(production of Irish whiskey is very similar).Detailed accounts of each of the unit processesin whisky production are given in subsequentsections of this chapter.A characteristic of Scotch malt whisky is thatthe only cereal used in its manufacture is maltedbarley (Table 1). After milling, the meal is mashedin a mash tun (Figure 2) similar to that used inbreweries for beer production. During mashingor conversion, enzymes in the malt catalyze thehydrolysis of starch into fermentable sugars. Inthe manufacture of Scotch grain whisky and Irishwhiskey, other cereals are used along withmalted barley to provide additional starch in themash tun (Table 1). Owing to the highgelatinization temperature of their starches,unmalted cereals must be precooked beforethey are incorporated into the mash.The wort, or clear mash, leaving the mashtun is cooled and fed into a vessel where it ismixed with yeast. In Scotland and Ireland thesefermentation vessels have a relatively smallcapacity and are known as ‘washbacks’ (Figure2).Fermentation is conducted with strains of theyeast Saccharomyces cerevisiae that are usuallyspecially propagated for the purpose, althoughScotch malt whisky distillers may use somesurplus brewers yeast (Table 1). The process isallowed to proceed to a point at which the