Barnaby’s Brewhouse: capturing CO₂ for a circular brewing economy

Barnaby’s Brewhouse, an organic microbrewery based in Buckfastleigh, partnered with Fab Lab South West to tackle one of brewing’s hidden environmental challenges — carbon dioxide emissions. Together they developed a prototype system that captures and reuses CO₂ released during fermentation to carbonate beers, reducing the brewery’s footprint and demonstrating how circular economy principles can drive innovation in food and drink production.

The challenge

Brewing naturally produces up to three times more CO₂ than is needed to carbonate beer, but most microbreweries vent this gas and buy in CO₂ from external suppliers — often sourced as a byproduct of the fertiliser industry. For Barnaby’s Brewhouse, certified organic and committed to net zero, this dependency conflicted with their ethos and left them vulnerable to rising costs and national supply shortages.

Our approach

• Collaborative prototyping: Working with Fab Lab South West, Directors Barnaby Harris and Tim Stacey co-designed a capture and purification system to recycle fermentation CO₂.

• Technical expertise: Ian Hankey, Principal Technician, contributed his experience in gas engineering and digital fabrication, designing and 3D-printing components and sensors. Where costly imports were needed, parts were re-engineered and fabricated locally, even using the University’s hot glass facilities.

• Iterative testing: The system was trialled on-site at Barnaby’s Brewhouse, focusing on filtering oxygen and odours to achieve food-grade CO₂ ready for reuse in beer production.

Results & impact

• Carbon savings: Once fully implemented, the system will capture more CO₂ than the brewery requires, enabling surplus to be offered for other uses.

• Circular economy innovation: Barnaby’s is exploring applications for captured CO₂ in horticulture and polytunnels, with potential to reduce pests and increase yields for local growers.

• Sector leadership: The brewery reached the finals of COP26’s “Heroes for Net Zero” awards for small businesses and continues to champion evidence-based sustainability.

• Path to product: With Fab Lab South West’s support, Barnaby’s is seeking funding to package the system as a commercial kit for microbreweries and fermenters, making carbon capture more accessible across the sector.

Technologies used

3D design and printing • Gas engineering • Digital fabrication • Custom glass components • Sensor integration

Partners & credits

• Barnaby’s Brewhouse — Directors: Barnaby Harris, Tim Stacey

• Fab Lab South West, Arts University Plymouth — Technical lead: Ian Hankey; Knowledge Exchange support: Ben Mundy

Impact Lab partnership — Collaboration supported by ERDF funding