Gadds’ and Toast Ale brewers have joined forces to create a special-edition beer to mark Earth Day.

Earth Day IPA (4.4 per cent ABV) is a cask beer with notes of passion fruit, peach, grapefruit and tropical fruits designed to showcase innovative action for the planet.

The theme for this year’s Earth Day (22 April) is about investing in our planet. Gadds’ already has a solar array to power chillers and an air source pump for space heating at the brewery. It also recently trialled new technology for small-scale carbon capture.

Carbon captured by the growing barley is released as CO2 during fermentation. It’s usually vented to the atmosphere by all but the biggest breweries, while CO2 produced from fossil fuel sources has to be purchased for carbonation and filling. The cost of CO2 has increased significantly over the past couple of years, and supply has been intermittent, making its capture for reuse a win-win for the planet and brewer.

Toast’s signature approach to reducing environmental impact is to use surplus bakery bread. This avoids emissions from what would otherwise be wasted food and reduces the need for malted barley, which has a large footprint. Dried, crumbed bread replaces five per cent of the malt. Other ingredients include raw barley, which doesn’t require the water and energy used for malting. For the remaining malt, which is needed for the enzymes to break down the sugars for fermentation, the brewers used a pale version. This requires less time in the ovens than darker malts so uses less energy.

East Kent Golding hops, grown close to Gadds’ were used with other UK hops.

Other techniques used to minimise the environmental footprint of the beer included high gravity brewing and the use of enzymes for cleaning instead of caustic chemicals. The final beer is also vegan-friendly.

Gadds’ head brewer and owner Eddie Gadd said: “We’re not claiming this beer will save the planet, but we hope it opens discussions about how we can all help make a difference.

“Ours is the most ancient of industries, steeped in history and carried out using artisanal methods bestowed on us by previous generations. But that doesn’t mean we can’t change and adapt, while retaining the fundamental way we make beer and the consequent fabulous pint.”

Toast brewer Stuart Robson added: “Collaborating with Gadds’ has been a great opportunity for us all to trial new ideas and learn from each other, ultimately resulting in a great tasting beer that has a lower environmental footprint. We’re looking forward to sharing learnings widely, and inspiring and supporting more breweries to invest in our planet.”

All Earth Day Pale Ale will be sold in casks at Gadds’ brewery taproom and pubs in East Kent. It will also be pouring at Toast’s taproom, Good Company, on 26 April for Stop Food Waste Day.