For an industry where the status quo is a cause for celebration and words such as ‘modernity’ and ‘evolution’ are akin to cussing, Tennessee whiskey is sure kicking up a sandstorm right now.

Down in Tennessee they like you to think life is best savoured in second gear. This is good ol’ boy territory, a land of quaint customs and good old-fashioned politeness. It’s a place where the god-fearing folk don’t care too much for progress and prefer to cling to the traditional way of doing things. 

And the sedentary style of living extends to the state’s whiskey producers. No matter that Jack Daniel’s is a massive business with five bottling plants and more than a million casks maturing in its warehouses: they like you to see the statue of Mr Jack and the old safe which indirectly caused his death. And George Dickel might be a southern outpost for drinks giant Diageo, but you’re more likely to be told about the distillery’s wild turkeys than how many millions of gallons of spirit it is capable of producing.

For generations life was pretty simple down this way. Two distilleries making a similar style of Tennessee whiskey, one of them among the most famous on the planet. But that veneer of peace and tranquility is being torn apart not by one tornado, but two. 

At the heart of both issues is the definition of Tennessee whiskey. Until a few years ago it wasn’t really an issue, because George Dickel and Jack Daniel’s produced their whiskey pretty much the same way, and the method they used effectively defined the category. Tennessee is, then, a style of whiskey very similar to bourbon, made with a mix of grains but predominantly corn or maize, and matured in virgin oak barrels.

But there are two important differences between Tennessee whiskey and bourbon. The first is that Tennessee whiskey obviously has to be made in Tennessee. Bourbon can be, and is, produced across the United States, including in Tennessee. The second difference is known as the Lincoln County process, and entails pouring newly distilled whiskey spirit through a wall of charcoal made from freshly burnt maple wood.

But the consensus was shattered when the American craft distilling revolution got under way. Suddenly Tennessee had several new distillers making a range of different whiskey styles. These, it has been argued, are whiskies from Tennessee but not Tennessee whiskies. 

The new distillers are split about the definition that was considered by the state legislature. Many feel that it is too close to the Jack Daniel’s recipe, making it all but impossible to make whiskey different enough to find a niche market of its own.

But many of the new producers support this view. Andy Nelson, co-proprietor of Nelson’s Green Brier Distillery in Nashville, says that his distillery produces a Tennessee whiskey and a separate bourbon. 

“We think Tennessee whiskey is a very specific style of whiskey, and of course being made in Tennessee is a major part of that definition,” he says. “Our view on the legislative issue is that the current definition of ‘Tennessee whiskey’ should remain as-is. Two of the main aspects of Tennessee whiskey are the Lincoln County process [filtering through charcoal] and ageing in unused, charred oak barrels. 

“The debate now is mostly in regard to new barrel ageing. This is a vital part of the process that if changed would damage the reputation of Tennessee whiskey worldwide. Ageing whiskey in a previously used barrel simply does not yield a product that is on a par with what the world has come to know as Tennessee whiskey and we want to make sure that consumers across the globe can equate Tennessee whiskey with the highest quality product and be proud of what they’re drinking.”

Nelson points out that Charles Nelson, the great great grandfather of he and brother Charlie, worked with George Dickel to get Tennessee defined as separate to bourbon. And as a result the brothers, along with several other craft distillers, fully supported the state legislature when it tempted to define Tennessee whiskey in law.

Steve Skelton of Beechtree distillery agrees. “Our Tennessee whiskey is styled a bit differently than most Tennessee whiskey,” he says. “I use a lower percentage of corn in my mash – about 60%–65%, as well as some great grains such as malted rye and barley. But the whiskey is charcoal filtered using sugar maple that we make ourselves.

“I totally agree with keeping Tennessee whiskey standards just like they are, using new barrels is part of that tradition. Jack and George made all this possible. I can go to anywhere in the world and people know about Tennessee whiskey.”

It’s somewhat ironic, then, given the history of the man who did so much to define Tennessee whiskey, that the distillery named after him not only opposed the new definition when it was first introduced, but is now set to challenge a key pillar of it.

Initially it opposed a clause stating that Tennessee whiskey had to be matured in Tennessee, arguing that such a rule would adversely affect free trade between states. Parent company Diageo moves George Dickel whiskey up to Kentucky though it denies it does so for maturation purposes, claiming the whiskey is blended and bottled in the neighbouring state.

It won that particular battle in June – but now Diageo is heading back to the courts to challenge the rule that requires distillers to use new charred barrels. Somewhat implausibly Diageo says that its move to allow barrels to be used more than once would make massive cost savings for the new wave of smaller distillers, increasing competition and allowing the craft distillers to experiment with new whiskey recipes.

Jack Daniel’s, owned by Brown-Forman, dismisses the claim. It has been at the forefront of the drive for a legal definition, arguing that clarity was needed to protect the quality of the spirit around the world. Jeff Arnett, master distiller at Jack Daniel’s, has gone further. He sees it as a callous attempt by Diageo to undermine the spirit.

“What we have here is nothing more than an effort to allow manufacturers to deviate from that standard, produce a product that is inferior to bourbon, and label it Tennessee whiskey, while undermining the process we’ve worked for nearly 150 years to protect,” he says. 

“It has been understood for 150 years that this is what Tennessee whiskey is. It’s only the fact that we’ve had a lot of new distillers that we feel like there need to be some rules for the playground, if you will, just to keep everyone honest.”

So why exactly is Diageo toying with the future of American whiskey? After, all, the use of virgin oak barrels has always been a unique selling point for the category. 

And, more significantly, scotch whisky relies heavily on the regular supply of ex-bourbon barrels and there would be a huge negative impact on the drinks giant should it dry up. What if George Dickel gets its way and then the bourbon industry follows suit?

There are two immediate answers. Firstly. Diageo is gambling – quite safely – on the fact that the bourbon industry would never go down that route. The benefits of taking the moral high ground when it comes to standards would far outweigh the benefits of cost cutting. 

And then there’s the other option: that Diageo doesn’t really care. George Dickel is tiny compared with Jack Daniel’s, and Diageo has only a token presence in the world of bourbon through Bulleit, which is little more than a brand name and is distilled at Four Roses Distillery in Kentucky.

So what’s the motivation? Simple, say critics. The end of the compulsory use of virgin oak barrels would seriously undermine the quality argument of Tennessee whiskey and cause massive damage to Jack Daniel’s.

Looking out for number one

Chuck Cowdery is a writer and one of the leading experts on American whiskey. He believes that with Johnnie Walker stalling (it receded at 4% for the year ending June 2014) and American whiskey in a purple patch, Jack Daniel’s could be a long-term threat to Diageo’s number-one world status.

“The number one ranking is not trivial,” he says. “It’s not just about bragging rights. 

“When newly affluent people gain access to luxury imported goods they immediately want to know what’s the best. They’ll inevitably start by looking at what’s number one. 

“Most people today, including most people in developing markets, know brands. They don’t know [whiskey] types. They don’t know Jack Daniel’s and Johnnie Walker represent two very different styles of whisky. The hallmark of the American style is the unique flavour profile you can only get with new, charred oak barrels. If the Chinese try Jack Daniel’s and like it, that will naturally align them with the American style.”

He continues: “The tide could turn. In the world today, scotch outsells bourbon five to one, but China and India don’t know that. India knows scotch because of the Raj, China doesn’t have an inherent favourite. If American whiskey, not scotch, becomes China’s choice, that could change everything. 

“Ultimately, this fight will be between big scotch and big bourbon. This is just the opening round.”

Drinks International repeatedly asked to speak to a Diageo spokesperson for this feature but no one was available. 

It should be said that any changing of the whiskey order is likely to be in the long term, if ever.

But what is clear is that Tennessee has gone from being sleeping backwater to the frontline of an international brands battle. And with the fight set to return to the courts as early as this month, life may never be quite the same for those good ol’ boys drinking whiskey and rye. 

Watch this space.