Glenmorangie Distillery tour with Dr Bill Lumsden

The tour begins at Glenmorangie’s main water source, the Tarlogie Springs. Situated in the Tarlogie Hills above the distillery, the spring is enough to satisfy its entire production needs.  “When the distillery is running flat-out we can do 33 mashes a week, which equates to 330 metric tonnes, giving us six million litres of alcohol,” says Bill. “To put that into perspective, some of the new so-called craft distilleries that are springing up will do 50,000 litres a year… The North British Distillery in Edinburgh, which produces grain whisky, can do about 150 million litres of spirit each year – so we are medium-to-small in the great scheme of things.”

To protect the water source from any potential impact that farming or property development could have, The Glenmorangie Company owns 1,000 acres of land surrounding the spring. The distillery also has two other back-up springs: the Kelpies, nearby, and “a third super-secret one”. “They’re all connected to the pipe that leads to the distillery,” says Bill. “They all have the same character of water and we can turn them on and off as required.”

This is one of the distillery’s malt storage areas. Floor maltings closed at Glenmorangie in 1977, when the distillery doubled in size to four stills. The site doubled in size again in 1994 to eight stills, adding a further four stills in 2009 to reach 12 in total. When running at full capacity, the maltings could produce approximately 30 tonnes per week, Bill says – 300 tonnes short of its current requirements. Another issue that lead to its subsequent closure was the “unbelievably inconsistent” quality from floor maltings. “The sales malts are malted to our own unique specification,” he adds. The barley Glenmorangie uses is 100% Scottish, and around 85% of it is harvested from within a 75-mile radius of the distillery. “It doesn’t need to be – the barley from England, from Germany, from France is perfectly good quality – but we just like the idea of keeping things local,” says Bill.

The next stop on the tour is the mill house – “on the face of it a relatively unexciting part of the process, but to a geek like me this is a magnificent thing to see,” says Bill. The distillery houses a classic four-roll Porteus mill. The top set of rollers, which crack the malt kernel open, are set far apart, while the bottom set of rollers are adjusted depending on the barely variety. Milling a 10-tonne mash takes about two and a half hours. At the end of each day, mash men draw samples of the ground malt, or grist, and weigh out 100 grams. The sample is poured into a sift box and shaken 60 times, separating it into three portions: husk, grits, and fine flour. “Typically we’re looking for a 20:70:10 ratio,” says Bill, “it’s critically important that the distillery team stay on top of the particle size ratio”. Failing to do so will affect yield and slow down production. Once the grist has been through the mill, it’s stored in grist hoppers for a maximum of three to four hours.

We press on to the mash house – where the grist is loaded into the mashing machine. At the same time, preheated Tarlogie spring water comes out one of two heating tanks. “At this stage, we must ensure that the strike temperature – which is the temperature of the cool ground malt as it hits the hot spring water – equalises out at 63.5 degrees celcius,” says Bill. “One or two degrees either side will have an impact on the conversion of starch to sugar.” The entire process takes place upon what is referred to as a “false bottom” – a series of fine mesh plates. Sugary “wort” is drained out of the bottom into balancing vessel called the underback. From here, the wort goes through a heat exchanger, where it is cooled and then pumped into the washbacks for fermentation.

To ferment the wort, three different sets of water are run through the washback. “The first and second waters are combined – the second water goes on at a slightly higher temperature,” says Bill. “The third water takes the remaining 2% out… and goes back into the heating tanks to be used as the first water of the next mash. We’re wasting nothing.” The remaining draff is rich in protein, oil and fibre – and so is sold to local farmers to feed cattle and sheep.

The next stop is the still house. Here, the fermented wash is filled into wash stills, where an oily liquid called low wines is produced. “We have a completely balanced distillation, which basically means one washback will fill four wash stills, which in turn will fill four spirit stills – so we don’t get dummy runs or inconsistent strength of spirit,” says Bill.

The distillery operates with 12 collecting bowls in the spirits safe, shown in the centre of the image. The first cut – or “heads” – of the distillation come into the still at around 74-75% alcohol. The still house men then cut to the heart of the distillation; manually separating the flow into the Intermediate Spirit Receiver. They then run the stills very slowly until the strength goes down to 60% abv, before collecting the third cut, the “tails”. The heads and the tails are mixed together with the next batch of low wines, and the entire process starts again. “At the end of the spirit run the strength is always 68% abv,” says Bill. “If it ever varies from that, we know something has gone wrong in the production process.” All being well, the new make spirit is destined for the warehouse.

“Glenmorangie is arguably the archetypal single malt Scotch whisky matured in American oak, and historically we believe we were the first company in Scotland to use ex-Bourbon barrels” says Bill. “We’ve got records going back to the late 1940s showing the company importing American oak Bourbon barrels. That kind of set a trend, and nowadays around 90% of all Scotch whisky is matured in American oak.” Glenmorangie’s policy, however, goes one stage further, with each barrels manufactured to the distillery’s specification. The whole process takes eight years from start to finish. “The cost of one of these standard barrels there is about four times the cost of a standard Bourbon barrel – but more than anything else I think this is the real difference with Glenmorangie.

So, how does the process work? “What we’re looking for is so-called slow-growth or tight grained oak – between eight and 12 growth rings per inch,” says Bill. “Any more than that and the wood becomes too brittle, any less and the wood becomes too heavy and dense and you don’t extract as much flavour from it.” Once the optimum trees have been identified, they are transported to sawmills in Tennessee and Arkensas and quarter-sawn into staves. “The normal practice for a stave like like that is to dry it in an oven, which will take anything between two and six weeks, but the wood’s still very immature, very green, and you get a lot of resinous characters,” Bill explains. “Our wood is allowed to season naturally in the open air for a minimum of two years, typically between two and three years. The wood matures, the tannins [are] broken down, the internal structure relaxes and it releases more of these nice vanilla and crème brûlée flavours.”

The staves are then sent to the Brown-Forman cooperage in Louisville, Kentucky and coopered into 200-litre capacity barrels. “The standard practice for a Bourbon barrel is to give it a very heavy char – a so-called alligator char,” explains Bill. “Our barrels are toasted using heat rather than naked flame for around three hours, which penetrates much more deeply into the wood; it’s a much more gentle process. It’s then given a 30-second char.” The heads are put on the barrels and filled with American whiskey for four years prior to being shipped back to Glenmorangie. Does it matter which whiskey is used? “Frankly from my perspective it doesn’t matter, as long as it’s got a first filling of spirit to take the woodiness out.”

After 10 years’ ageing, some whisky is bottled and the remainder is re-filled for a second time – no barrel is ever used more than twice for any Glenmorangie expression. The remaining 10 Year Old whisky is either set aside for older age statement releases or re-racked into an Oloroso sherry butt, a ruby Port pipe, or a French oak sauterne barrique, where it is finished for around two years. This is how the brand’s Lasanta, Quita Ruban and Nectar D’Or variants were developed.