An important, and often overlooked, part of brewing is what happens to the spent grain. At Bluntrock, instead of becoming waste, it begins a second life just over the hedge from the brewery, helping to regenerate soils of our surrounding fields and to support food production right here in our little pocket of Cornwall.
The After Life of Our Malt: From Brewing to Regenerative Agriculture
During the brewing process, malted barley is steeped in hot water to extract the sugars that will eventually ferment into our beers. Once that process is complete, we’re left with spent grain - the husks and fibre of the malt, still packed with valuable nutrients, particularly nitrogen.
Rather than sending this nutrient-rich by-product off site or to landfill, we donate it directly to local farmer Hartley Hore, who runs Restharrow Farm in Trebetherick, and farms the fields directly surrounding our brewery.
This partnership helps to improve resource sourcing local for Hartley, therefore reducing transport emissions, and ensures nothing on our end goes to waste.
How Spent Grain Improves Soil Health and Crop Growth
According to Hartley, spent grain is an incredibly effective soil improver when used correctly. Its benefits include:
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High nitrogen content, supporting strong early plant growth
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Use in compost production, where it boosts micro-bacterial activity
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Improved soil fertility, structure and water retention
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Support for crops with high nitrogen demand in early stages
Hartley uses our spent grain in several ways across his fields:
Onions and Brassicas
Spent grain-enriched compost is used to support crops such as onions and brassicas, which benefit from nitrogen-rich soils during early growth.
Spring Barley
For spring barley, the grain is spread across fields in winter and incorporated into the soil. In spring, it is used as a top dressing, feeding crops and stimulating soil biology just as growth begins.
This regenerative approach improves long-term soil health, supports microbial life, and reduces the need for synthetic fertilisers.
Supporting Local Food Systems at Restharrow Farm Shop, Trebetherick
Some of the crops grown using these soil-building methods contribute to produce sold locally, including through Restharrow Farm Shop in Trebetherick, which is run by Hartley’s family. The farm shop champions all of the seasonal, locally grown vegetables grown at Restharrow Farm, and offers a direct connection between farming, food, and the community around the Camel Estuary.
Brewing With Biodiversity in Mind
To help us secure the planning permission for our new brewery, we developed a biodiversity plan to ensure the site fits naturally into its surroundings.
This includes:
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Green spaces in and around the brewery site
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Wild flower and tree planting to support pollinators and wildlife
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Habitat-friendly landscaping
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Natural integration with surrounding farmland
Our goal was simple: to operate a brewery site that enhances, rather than disrupts, the landscape it sits within. If you come to the brewery in the spring you'll probably find George tending to the trees, planters, or the natural pond in the corner of our yard while in and out of the brewery.
By giving our spent grain to Hartley, it's kept in the ecosystem in the land directly around the brewery, contributing to healthier soils, more resilient crops, and a greener environment around the brewery itself.
A Circular Economy: Beer, Soil, and Community
Even though Hartley isn’t growing barley for us to then eventually use in our beers, we’re pretty happy with how close we are to achieving a circular economy approach with our spent grain; Malt becomes beer. Spent grain becomes soil nourishment. Healthy soil grows future crops. Those crops are then available for everyone in our local area, including our team at the brewery, to eat and enjoy.
It’s a reminder that sustainability isn’t always about complex technology, much like our carbon capture system - sometimes it’s about making the most of strong local relationships, making practical decisions, and respecting the immediate land we’re part of.
Next time you enjoy one of our beers, you can be confident that what’s left behind is helping the fields surrounding the brewery grow stronger, and the produce available at Restharrow Farm Shop taste even better!
Thank you to Hartley and his family, and all of the wonderful people working for their farm, for allowing us to dispose of our spent grains in the most positive way possible.
P.S. The Restharrow Veg team's favourite Bluntrock beer is none other than Wasson, our 3.4% Pale Ale.
