Head off on any distillery tour and it won’t be long until the touring party arrive at the washbacks. Often pine, sometimes stainless steel, this is the stage in whisky production where yeast is added to the sugary liquid and a beer-like wash is created. Not only does fermentation produce alcohol and carbon dioxide, but a whole load of flavour compounds – or esters – join the party, too.

As a result, there’s often a narrative that the longer the fermentation, the better those flavour compounds. Industry-standard fermentations come in at about 48–60 hours, but some distilleries will go much longer. The deciding factor though is not the quality – it’s the flavour profile being sought.

Esters form at different temperatures, different times, and with different yeast strains. In fact, there are dozens of different variables that affect what esters will form. Often, it’s only through trial and error that producers will discover what works best for them and their spirit.

“From the get-go we wanted to get a better understanding of the whisky-making process, and so we looked in detail at flavour creation,” explains Max Vaughan, co-founder at Derbyshire’s White Peak Distillery. He uses live yeast from a local brewery for his ferments and started standard-length trials back in 2017.

“We were seeking out the fruity esters that we expected to find in the longer, bacterial phase of fermentation. In the final spirit, we also have to consider the various elements that mashing and distillation can bring into play. Putting those aspects to one side, we found the flavour profiles we wanted among the longer fermentations.”

In White Peak’s case, longer worked well – predominantly because the team wanted to encourage the growth of flavour-forming bacteria that only comes in later on. That won’t suit all distilleries. The whisky character of others might shine with shorter fermentation cycles.

“We’ve also found, in our case, a tipping point where we don’t see a fundamental flavour benefit in extending the fermentation,” Vaughan continues. “So, a longer six-day fermentation is a key part of our regular whisky making, but it’s a considered decision around an overall desired flavour profile.” There will always be a ceiling point. Longer is not inherently better – 48, 60, 80, or 150 hours all create different outcomes, and what’s preferable for one distillery won’t work for another.

Another common stage on a distillery tour, especially if that distillery is in a picturesque location, is a short hike to visit a water source. The narrative broadly includes the words ‘pure’, ‘distinct’, and ‘flavour’. The implication is that this water makes the whisky distinct and has a major impact on the distillery character.

But, as McCarron explains, there’s much more to it. “If I was building a distillery tomorrow, I’d won the EuroMillions and I could finally do it, the most important thing is to have a plentiful supply of water that is potable, drinkable, and has no taints in it. And that’s it. That really is the key to making whisky.”

He says that 50 years ago the circumstances were slightly different. “There was less scientific research, and less interest, frankly. There was a lot that wasn’t understood about fermentation, mashing, and character.” But that doesn’t necessarily mean things are better now than they were then, he adds. “A lot of things were assumed to be down to the water – at that time it made sense, but now we understand more.”

Interestingly, while it’s not to the extent that some whisky marketing suggests, water does have an impact. “There are some exceptions that prove the rule,” McCarron says.

Whether water is hard or soft will affect how a distillery creates flavour. “Hard water is full of salts like magnesium and calcium, and these really help to settle the enzymes during mashing. It’s really beneficial,” he outlines. The make-up of the water can also affect how flavours are formed during fermentation.

“That doesn’t mean if you have mineral-rich water you will always make a fruity spirit. It depends on how you use it,” he continues. Still shape, distillation cuts, cask maturation, and blending will all either accentuate or erase its impact. “There are 100 things at play, and one of them is water.”

It’s a real quirk of whisky marketing. In a highly regulated industry, it comes as a surprise to many that the words ‘craft’ or ‘small batch’ on a product label have absolutely no weight. So much so that back in 2015, a senior Diageo executive described Johnnie Walker as “the largest craft whisky in the world”.

“They are cornerstone phrases of the artisanal spirits movement!” Woven Whisky co-founders Peter Allison and Duncan McRae state over email. “It’s interesting that they are often discussed together, and I think that highlights the ‘hidden meaning’ we infer in their use.”

Allison and McRae agree that the terms lack a precise definition in spirits, despite many working hard to address it. “Since it’s not a strictly protected term, I agree it’s open for use by those who might not fully meet its implied criteria,” Allison adds.

For them, although the terms are open to misuse, they still hold significant meaning for people. “It’s about going against the grain of maximum productivity and efficiency. Ultimately, it’s our desire for a more personal connection and experiences that are tailored for us, rather than treating us merely as generic consumers. We seek that sense of connection, and the notions of craft and small batch provide that.”

Some markets are actively addressing the issue of the “commercialisation of craft”, Allison and McRae explain. “In Australia there’s a ‘certified independent’ stamp for indies that is helping deal with the confusion of craft beer. We’re not saying that indie equals craft, by the way!”

There’s another angle to this that is becoming more pertinent. What happens when a ‘craft’ brand – that meets the generally accepted public definition of the word – is acquired by one of the big companies? “The lines are well and truly blurred,” the pair continue. “I don’t think we can stop (nor should we want to) multinationals using the word ‘craft’. There simply exists two worlds: a true craft and a faux craft.”

While ‘small batch’ may be easier to define, it’s likely to also remain a relative term, they say. What’s key to remember is that neither of the terms have any legal or legislative definition. The onus is on whisky drinkers to explore whether they think a brand meets their values in this area.

This is a topic rife with misconceptions. Colour (legally) gets into a whisky one of two ways: through cask influence, and by adding caramel colour, or E150a. Considering there’s not a requirement for whisky companies to disclose the use of colour in their products, it becomes a murky topic.

There are two things to note in this debate. Firstly, the use of caramel colour is not inherently bad. Its intended purpose is colour correction for consistency, not to mislead whisky drinkers. Secondly, casks don’t impact consistent colour. Even taking into account previous contents, time, and size of the vessel, there will always be differences in how active they are.

“If there was no [such] thing as E150a, colour would be a useful indicator,” McCarron ventures. “But there are always going to be exceptions to the rule.” To be clear, he’s not advocating for it being banned. “But all bets are off when caramel colour is there.”

The colour imparted by casks, he says, is “generally” a reasonable indicator. “Most of the time, they’ll do what you expect them to do.” He sees the appearance of a whisky as being as useful as knowing the region it came from (in a Scotch context): you’d expect a Speyside expression to be reasonably fruity, “but then there’s some really smoky Benriach.” It’s worth noting the extent to which we taste with our eyes. A mahogany whisky may well bias the taster towards sherry cask-type notes.

While businesses rarely declare the use of E150a on their labels (unless exporting to or selling in a country where this is required), many who don’t use it choose to make that known. Look out for ‘natural colour’ on a bottle – that’s a safe indicator of the absence of colouring. But again, just because a whisky is bottled at natural colour doesn’t mean it’s inherently ‘better’.

“If I was told, make a decision, should caramel colour be allowed, I’d say let’s get rid of it because it does create more mess,” McCarron states. “Then everyone celebrates, yay!” But he notes there would be a significant downside. As explained at the outset, whisky is complicated. A change like that could make it more so.

“Whisky is really, really tough to understand,” McCarron continues. “I genuinely believe it is becoming a friendlier place and less intimidating, but it’s still quite hard and there’s just so much to learn.” For people picking up their favourite whisky, the drinks cabinet staple, variance in colour could cause confusion. “They’re going, ‘Great! I’m finally starting to understand this.’ And then they get to the shelf and there are two batches that are slightly different colours. How do you explain that? They’re exactly the same whisky. They taste exactly the same, or as close to exact as whisky will ever be. It’s just natural cask variation. And it makes it even more intimidating to get into whisky.”

McCarron agrees that there should be limits on how much colour is added, but stresses that any step forward in this area should make sense for all whisky drinkers.