Farmers, brewers and merchants have been trialling new varieties of organic hops that are resilient to climate change amid concerns over the future of British-grown beer ingredients.

A group of cross-industry researchers have been developing crops over the last three years that can be grown organically in warmer temperatures and are more resilient to diseases.

The Innovative Farmers’ Hop Trial aims to bolster the UK’s cultivation of hops, which provide more flavour to beer on top of the base malt, after decades of declining production.

The traditional non-organic varieties grown in the UK, like Fuggle and Goldings, are under increasing stress from issues like climate change, disease and insects, and low nitrogen availability.

They have also seen a fall in demand due to changing consumer tastes towards tropical flavours produced by hops that have been imported from countries like the US.

Greg Pilley, managing director of Stroud Brewery in Gloucestershire, said that growing more climate change-resistant organic hops in the UK could supply farmers with a high quality, sustainable crop.

“We’re now moving into the fringes of hop growing really,” he said.

“The underlying issue is climate change – our weather is changing.

“UK summers are becoming wetter and more humid and less reliable, and it’s making hop growing more challenging.”

Growing trials on two farms in East Sussex and Worcestershire have identified five varieties of hops that showed promise in coping with higher temperatures and increased disease resistance.

After being harvested, Stroud Brewery used them to create new beers, which were put to a tasting trial in its taproom last week to assess their suitability for commercial beer-making.

Industry specialists said Harlequin, a hop that is already conventionally grown but had not been produced in an organic setting, and newer varieties called Endeavor and 302 had particular potential.

They said these had not only shown higher resilience to disease but produced exciting flavours, with notes such as “pineapple”, “strawberry laces”, “blackcurrant”, “spice” and “lemon”.

Rich Davies, sales manager at Charles Faram, a beer merchant which helped to run the development programme, said this project has been the first time they have seen new organic varieties produce a bigger yield.

“Nine times out of 10, people find a hops variety that they absolutely love but then you put it in a plot, you try to grow it and it’s susceptible to wilt or spider mite and it’s just a non-starter,” he said.

“It has to be a balance of both – something that’s exciting and new that’s got the aroma and the punch to go forward but will produce good yields as well.”

Mr Davies said that these varieties will not provide the same intensity of taste compared to those like Mosaic, Simcoe or Citra, but brewers could switch in 30% of these hops with Harlequin.

“You’re not going to notice any discernible differences in the finished beer but it’s more sustainable, there’s less miles travelled from the farm, and it’s more cost effective for brewers as well so it helps all around,” he said.

The variety Endeavor has also been growing on Tedney House Farm in Worcestershire, with the first kilo and a half harvested used in the Stroud Brewery tasting trial.

“It works,” said the farmer, John Walker.

“We think we can grow it.”

Meanwhile, Tom Upton, from Woodlands Farm near Rye in East Sussex, said the variety 302 was going to be ditched by conventional farmers because of its susceptibility to wilt but it has grown successfully on his organic farm.

“It’s clearly turned out to be a very good marketable hop to make very good beer,” he said.

More widely, Mr Upton said the development work could have bigger implications for the British industry as a whole.

“The day’s rapidly approaching whereby conventional growers will either have to go out of business or they will have to adapt to growing in a manner perhaps similar to a way that we do now,” he said.

“So it’s an important project, not just for a very niche organic market but for the hops industry in general, where it’ll have to adapt to some of practices that John and I are pioneering.”

He added that the programme can also “offer a degree of hope in an otherwise dismal outlook for the conventional industry”.

In terms of what happens next, Mr Pilley said his longer-term ambition is to gather data on the increased biodiversity and soil carbon on the organic hops farms, and compare it to their conventional neighbours, to help tout the environmental credentials of the beer they sell.

“In order to create a market for organic farming, we still need that evidence and increasingly so in order to verify our claims,” he said.