Last week, the brewery told The Morning Advertiser ​that it had designed a new manufacturing technique​, which involves breaking up bourbon and rum barrels and toasting the pieces, before circulating the beer through them for between five and ten days.

The brewery said the new process means its beer can be called barrel-aged, as opposed to oak-aged.

However, Steve Dunkley, owner of Beer Nouveau in Manchester, has hit out at the claim, while other breweries and commentators have expressed doubts over whether the process can be described as barrel ageing.

Dunkley said: “Barrel ageing is letting beer mature in barrels. It’s done for many different reasons, to impart the flavour of the wood or the previous contents of the barrels, whether they be virgin oak or used whiskey, wine, sherry or port barrels. Beer is put into them and left to work with the wood over time.

Spot the difference, one photo contains barrels, on contains a piece of wood. pic.twitter.com/b18xI1EHpi — BeerNouveau (@BeerNouveau) October 17, 2017

'Not barrel ageing'

“This isn’t what Innis & Gunn are doing. For a start there’s no barrels involved. A barrel is a thing, a piece of wood is another. Imagine buying a house and being presented with a single brick? The wood may once have been part of a barrel, but it is no longer.

“They’re not ageing either, they are filtering for up to ten days to infuse the flavours from the wood,” he continued. “Calling that ageing is a bit like a child calling themselves an adult as soon as they’ve got their first spot, it takes a bit longer than that.

“Different beers age differently in different barrels with different yeasts. Forcing this out quickly like they’re doing is akin to repeatedly squeezing and resqueezing a teabag rather than using a pot to try to make a decent cuppa.”

Others took to social media to share their anger. Suffolk microbrewery Little Earth Project, which specialises in barrel-aged beer, tweeted: “When we say something is barrel-aged it's not just shown a few staves for 5-10 days!”, while CAMRA activist John Clarke added: “Surely ‘barrel-aged’ means actually aged in an actual barrel? Or have I missed something?”

Is it just me but surely "barrel aged" means actually aged in an actual barrel? Or have I missed something? — John Clarke (@Beer4John) October 16, 2017

'Engaging in a debate'

Responding to the criticisms, Innis & Gunn founder and master brewer Dougal Sharp said the brewery had been entirely open about how their beer was being made, adding that their process was barrel ageing “reinterpreted for today’s modern, vibrant craft brewing scene”.

“You can’t escape the fact that these are barrels which we have broken up in a process that is unique to us,” he said. “It isn't the traditional use of barrels but we are not claiming it is. We are very clear that we put the barrels into the beer on our packaging, and the full description of the process is on our website.

“We're doing interviews like this to explain our thinking and engage in a debate. We completely stand behind our claim that this is barrel ageing, it's just reinterpreted for today's modern, vibrant craft brewing scene.”

He continued: “As a business we have never been hung up on trying to prescribe to others what something should be. But we have been barrel-ageing for 15 years, and arguably we have some of the most experienced people in the world at barrel ageing.

“We do what is right for our beer, and the proof is in the pudding. It's great to have the debate but, ultimately, it is all about the beer and what it tastes like. This new technique, combined with the technique we have already got, gives us capability we would never have otherwise had.”

The Morning Advertiser​ contacted Trading Standards to find out if Innis & Gunn’s claim was misleading to consumers, but were told that no industry standard definition of barrel ageing exists.