The New Midleton Distillery exists because three of Ireland's old distilling families decided, in 1966, that survival meant losing their separate identities. John Jameson & Son in Dublin's Bow Street, John Power & Son in John's Lane, and the Cork Distilleries Company in Midleton merged that year to form Irish Distillers. The new company's directors weighed up the old buildings - Bow Street and John's Lane had been distilling since the 1780s and 1790s respectively - and concluded that none of the existing sites could be expanded enough to compete with the Scotch industry's modern plants. Only Midleton had room. They closed Bow Street, closed John's Lane, and in July 1975 they switched on the new distillery built right beside the Old Midleton Distillery they were also retiring. The brands moved with them. Today the buildings where Dublin's whiskey families made their fortunes are visitor centres and apartment conversions; their whiskies are all distilled in County Cork.

What makes the Midleton plant distinctive is its flexibility. The three pot stills can be run independently or as a triple-distillation chain, the way Jameson is traditionally produced. The three column stills, used in continuous operation, produce a lighter grain spirit. Different combinations of these stills, different cuts at different alcoholic strengths, different mash bills - all malted barley, or a mixture with raw unmalted barley for the pure pot still style, or fully grain-only - give the distillery the capacity to make almost any style of Irish whiskey under one roof. That is why a single distillery can be the home of Jameson (a blend), Powers (also a blend, with more pot still character), Paddy (lighter blend), Redbreast (single pot still), Midleton Very Rare (a blend), and Green, Yellow, Red and Blue Spot (all single pot still). Beside the giant stills sits a micro-distillery with small pot stills that produces about 50,000 litres a year of experimental spirit, used for new releases and for training.

Since 2010, Irish Distillers has been spending. More than 200 million euros went into doubling capacity, adding a third pair of stills, installing fibre-optic networks between the production areas, and building a vast new maturing facility at Dungourney, a village a few kilometres east of Midleton. The reason was demand: Irish whiskey has been the fastest-growing spirit in the world for three decades, with exports climbing at more than fifteen percent a year. Jameson alone now sells more than ten million cases annually, and the brand has roughly tripled its sales since 2010. Pernod Ricard, the French drinks giant that has owned Irish Distillers since 1988, has kept investing. The plant now operates around the clock, its fibre-optic systems letting one control room oversee mashing, fermentation, distillation and warehousing across a campus of buildings. It is, by most measures, the largest whiskey distillery in the world.

Beside the working distillery sits the Old Midleton Distillery, the 1825 stone-and-slate complex that Irish Distillers retired in 1975. They did not knock it down. Instead they turned it into the Jameson Experience, a visitor centre that brings somewhere around 100,000 tourists a year through its courtyards. The tour walks visitors through reconstructed milling and mashing scenes, the seven traditional stages of whiskey making, and a video about John Jameson, the Scotsman who came to Dublin in the 1780s and gave his name to what became Ireland's most famous brand. The Old Distillery still houses the largest pot still ever built - 31,618 gallons, big enough that the still room walls were built around it. The seven-metre working water wheel is the largest in Ireland. A taste test at the end of the tour offers visitors a chance to compare Jameson with Scotch and bourbon and earn a paper certificate as a Qualified Irish Whiskey Taster.

In 2013, the distillery opened the Irish Whiskey Academy in the grounds of the Old Distillery - a serious training institution offering one-to-three-day courses on whiskey history, production, sensory analysis and brand history for industry professionals, journalists and serious enthusiasts. The original Master Distillers House on the same grounds now holds the official historical archives for the Irish Distillers brands, a working library and reference collection used both for marketing and for genuine scholarly research into the spirit's history. A retired master distiller named Barry Crockett, born and raised on the site - his father was a master distiller before him - was brought back from retirement in 2014, together with his successor Brian Nation, to produce a 30th anniversary edition of Midleton Very Rare. They made exactly 117 bottles. Each was numbered. They sold instantly to collectors who knew what 117 numbered bottles by Barry Crockett would be worth in twenty years.