In exclusive interviews with the Daily Mail, two expert distillers – one from the United States and one from Scotland – shared their methods for creating their unique alcoholic beverages. Their insights shed light on the long-standing debate over whiskey versus bourbon.

Despite being located on opposite sides of the Atlantic Ocean, Kings Co Distillery in Brooklyn, New York, and Glenkinchie Distillery in East Lothian, Scotland, both prioritize the precise and scientific art of making rich and smooth spirits.

Both distilleries adhere to traditional processes such as malting, fermenting, distilling, and aging their products. Interestingly, they often finish the aging process in American oak barrels, a common practice that adds unique flavors to their spirits.

While the core processes are strikingly similar, subtle distinctions – and legal requirements unique to each country – create key differences, such as bourbon, which by law, can only be produced in the United States.

Founded in 2010, Kings County Distillery crafts American whiskey, bourbon, rye and single malt entirely grain-to-grass, right along the historical Brooklyn waterfront. 

‘We are the first craft distillery to open up in New York City since prohibition,’ Colin Spoelman, cofounder of the distillery, told the Daily Mail.

While whiskey – or whisky, depending on where you are – is broadly defined as a distilled, alcoholic beverage made from fermented grain mash, bourbon is uniquely American: a distinct type of whiskey bound by strict US legal standards.

One key standard is the grain mash, which must be made up of at least 51 percent corn to qualify as bourbon – and at Kings Co, they have plenty of it.

‘Once a month, we’ll use this yellow tube, which is a transport auger, and we’ll have a tractor trailer come and essentially dump 40,000 pounds of corn up the tube into one of our two grain silos,’ Spoelman explained.

‘All of our grain is grown in upstate New York, and then we also use a lot of barley,’ he added. ‘The barley that we use is imported from the United Kingdom.’ 

Meanwhile, over 4,000 miles away, Glenkinchie’s brand ambassador, John Johnstone, is busy crafting Scottish whisky at one of the Four Corners distilleries of Johnnie Walker.

The process begins with water and spring barley. As the barley grows, it produces sugar, which is stored in the grain as starch. 

To access the sugar, the starch must be converted through malting. By controlling the natural process of germination, the starch is unlocked and transformed into sugar, which is then used to create alcohol.

The process is much the same for Spoelman’s crew across the Atlantic, though their recipe may include ingredients like corn, yeast and the unmistakable touch of classic New York City tap water.

Mashing is the next step. However, in Scotland, the process looks a little different – the grains are steeped and made into more of a tea-like consistency.

In the video, the two distillers walk through the step-by-step process of transforming the raw, clear spirit into the rich, golden liquid found in stunning glass bottles on shelves – one of the biggest differences lying in how and where their spirits are aged.

‘American whiskey requires charred new American oak barrels,’ Spoelman explained. 

‘We fill about three to four barrels a day, depending on what recipe we’re doing, and we can only use the barrels once to be called American whiskey, so most barrels end up becoming Scotch whiskey barrels for their second life.’

Across the pond, Johnstone showcased rows of reused American oak barrels, explaining how the rough, seasoned wood imparts bold new flavors to the maturing spirit.

‘You’ll find that more than 90 percent of Scotch whisky will mature in bourbon casks,’ Johnstone told the Daily Mail.

‘The law in the United States only allows their industry to use the barrel once, then they have to get rid of it,’ he added. ‘We could use that barrel for another 100 years.’

After three years, the liquid will finally begin to taste like a real, true whiskey.

Bridging two worlds an ocean apart, the two distillers – joined by Johnnie Walker’s master blender – had the rare chance to taste each other’s creations firsthand.

‘I have not been to this distillery, I don’t know this distillery very much,’ Spoelman said after being handed a bottle from Glenkinchie. ‘It’s my first time trying it, I can’t wait. I’m excited about this.’

Smacking his lips after the first taste, Spoelman described the Scottish whiskey as a ‘classic scotch, more creamy and vanilla’.

‘It’s not super overbearing, it’s not super singular – the nice thing about it is that depth of flavor I recognize a little bit from our own whiskeys, so for that, I like it,’ he said in response to the transatlantic sip.

Johnstone, staring at the glass of Kings County whiskey in his hand, said: ‘Can I just say what a privilege and a pleasure it is for me to be trying a whiskey that’s been made some 3,000 miles away. Absolutely wonderful.’

‘Really, really lovely,’ Johnstone said after indulging in a taste, noting how he picked up on hints of spice. ‘If you’re in to smoky whiskey’s, you absolutely would love it.’

After trying the Manhattan-based whiskey, Emma Walker, Johnnie Walker’s blender, said: ‘That’s lovely – that lovely spicy, softness, sweetness and vanilla that comes through’.

‘I’m looking forward to hopefully, in the near future, being able to come to New York, to Brooklyn, and to be able to try the whiskeys with you in person.’