Coffee Logs: sustainable solid fuel from recycled coffee grounds
Coffee Logs by stove


20th December 2022

Coffee Logs: sustainable solid fuel from recycled coffee grounds

Coffee can fuel not just your day, but also your fire…

In the UK our coffee drinking habit and the production of instant coffee generate an estimated 250,000 tonnes of spent coffee grounds each year. But what happens to all those grounds once we’ve finished brewing and processing?

bio-bean Coffee Logs reduce waste and greenhouse gas emissions

Typically, spent coffee grounds are discarded with general waste and sent to landfill where they degrade and emit methane, a greenhouse gas with considerably more global warming potential than carbon dioxide. And if not sent to landfill with general waste, they’re often sent to anaerobic digestion (AD) with food waste, where, in high volumes they can inhibit the desired biomethane production. Plus, spent grounds are heavy, and so sink to the bottom of AD ‘bellies’, having to be scooped out and discarded after all.

Here at bio-bean, we divert spent coffee grounds away from landfill, AD, and other inefficient disposal methods and recycle them into new sustainable products. One such product is our solid biomass fuel for consumer use: Coffee Logs. Our process of diverting and recycling waste grounds into these eco-friendly fire logs saves 130% more in greenhouse gas emissions compared to the grounds going to AD!

bio-bean Coffee Logs are an efficient solid fuel

By recycling waste coffee grounds into Coffee Logs, not only do we reduce waste and save on emissions, but we harness the untapped energy contained in the grounds to give them a second life as a useful product. Spent coffee grounds have a naturally high oil content and therefore a high calorific value, making them an ideal energy source.

Before compressing the waste grounds into compact logs, the grounds go through an engineered drying process that allows us to ensure the moisture content of each log is below 12%, the perfect moisture for burning efficiently.

This, in combination with the naturally high calorific value, allows Coffee Logs to burn 20% hotter than kiln-dried wood. Which means you need fewer logs to achieve the same heat output. And Coffee Logs burn on average for an hour, depending on the appliance efficiency and its airflow control.

Coffee Logs are a sustainable alternative to coal-based fuels and imported wood logs

Coffee Logs are compact and designed for use in domestic enclosed appliances, such as wood-burners and multi-fuel stoves. Each log is made from the grounds of around 20 cups of coffee, which we receive from a wide range of businesses across the country, from independent coffee shops, high-street chains and office blocks, to railway stations and even airports.

But Coffee Logs don’t smell of coffee when they’re burning. Although there’s a slight aroma of coffee when you first open the bag of logs, Coffee Logs give off a neutral aroma when lit.

Coffee Logs are packaged in fully recyclable paper bags containing 16 logs, and are available online and in-store through retailers across the UK, including supermarkets, DIY stores and garden centres.

Want to know more about Coffee Logs? Head to our Coffee Logs website.


This blog has been updated from the original, posted 16th December 2019.