The fact that there are only three distilleries in Ireland would suggest that this has always been a small-scale industry. Take time to visit the Old Jameson Distillery in Dublin or the Jameson Heritage Centre in Midleton, County Cork and another truth is immediately apparent. These are distilleries built on a grand scale. Both sites are long silent, but give a glimpse of a time when Irish whiskey rather than Scotch was the world's favourite style.

No wonder distillers like Jameson and Power rejected the column still; the world wanted their pot-still whiskey. By the end of the 19th century, Jameson's Bow St. plant was employing 300 people and 2 million gallons were sleeping beneath the Dublin streets. But history stepped in and five years after the formation of Irish Distillers, the Bow St. site closed. Production was switched to Power's equally grand John's Lane distillery for three years, before the new plant at Midleton started up in 1975.

Much the same happened in Cork Distilleries' massive 'Old' Midleton distillery now (slightly confusingly) called The Jameson Heritage Centre. It's undoubtedly impressive, but like all silent distilleries, slightly sad and ghostly. Wandering round this vast plant you can imagine the scrape of the shovels in the malting barns, the creak of the pulleys, the hiss and rattle of the stills, the clatter of hooves in the cobbled courtyard, the cries and laughter of the men, the calming splash of the water wheel which powered the plant.

Then in 1975 the wheel stopped, the largest pot still in the world (at 31,648 gallons big enough to hold a party in) produced its last spirit. But the ending of the old world ushered in a new one of high-tech whiskey making. 'New' Midleton, carefully hidden from the tourists' gaze, may look unimpressively industrial from the outside, but is the most remarkable distillery in the world.

So why haven't we heard about it? Maybe the industry had been so badly beaten up that it lost confidence in selling to the world. Until recently that is. Jameson is currently the fastest-growing whiskey brand in the world, new lines are appearing at a rate of knots. But we skip ahead.

How can you make 30-plus different whiskies (and gin and vodka) in one site? The few visitors who are allowed into the Midleton still room spend an age shaking their heads in wonder at the four massive pot stills sitting opposite the seven columns that shoot up to the roof. 'Effectively, what we have here is two distilleries rolled into one - a pot still/malt whiskey distillery and a column still light/grain whiskey distillery,' says master distiller Barry Crockett, looking down into the cavernous stillhouse.

'What's unique is the way the distillate streams can be diverted from the pot still side to the column still side, and vice versa. Actually, I can use any combination that takes my fancy!' In other words, he can make a triple distilled pot still spirit, or pot-column-pot, or column-pot-pot, or ... well, you get the idea. Just through distillation, different flavour profiles are created. There's more. 'The cut points for each component whiskey will vary,' he says.

'Say we're making one for Jameson 15-year-old. It will have a different cut point to the standard Jameson. Power's and Paddy will also have their own different cut points, distillation techniques - and mashbills.' Most of the pot still whiskeys use a percentage of unmalted barley - giving them a distinctive crunchy, spicy quality. 'It's hard to describe.