As breweries and producers produce the extra stock for the season, the substantial amount of added waste exceeds what they could possibly handle. What’s more, breweries have grown in numbers over the years, with artisan breweries popping out to meet changing tastes. As a result, brewers are coming under increased pressure to do more good with the waste at the end.
What happens to leftovers now?
Around 85% of the ingredients used to make beer are left over at the end of the process — but it doesn’t all go to waste. The spent grains get used for other products. Left yeast is used to make Marmite. Grains are used to make cereal-based products and different types of animal feed, which is a good start.
The trouble is there are so many spent grains that, with their short shelf life due to moisture exposure, many start to go bad before they can all be used.
So, despite a large number of spent grains being used for other products, as much as 3.4 million tonnes are still scrapped every year.
To help breweries cut down on this waste and find other uses for it, scientists have been finding other ingenious ways of using grains, including turning it into biofuel.
The grains are being developed to help in the process of creating renewable energy, potentially helping to heat thousands of homes.
Dr Ahmed Osman, of Queen’s University, Ireland, has found a way of converting leftover barley from beer production to turn into active carbon.
First, the wet grain is dried out and treated with a special chemical wash, then heated. Over time, this process turns the leftovers into carbon.
Given prevailing concerns about carbon pollution, you might wonder how good the carbon is for the environment or if it’s linked to climate change. However, active carbon works differently. Whereas carbon dioxide is environmentally harmful, active carbon helps absorb harmful chemicals. It soaks up gases, poisons and other unwanted ingredients from the air and from water, which makes it useful for integrating into air and water infiltration systems.
When it comes to creating renewable energy, the active carbon created from the grains can also be used to remove gas contaminants during this process. Producing more active carbon helps the environment, with the potential to help more households provide renewable energy and communities with both water and air cleaning. Using more spent grains for this purpose means more waste from breweries going to good use.
It’s widely known that biofuel used as a petrol replacement can be created from plants and even cooking oil leftover from large-scale catering businesses.
Now, other companies are exploring this concept to achieve similar things.
After coming up with a way of using leftovers from whisky production to make biofuel, Celtic Renewables is establishing its own production plant in Grangemouth, Scotland.
It operates by gathering the wastage — or draff, as it’s called locally — from local distilleries and creating sustainable products, including biofuel. It uses the waste product to create acetone, butanol and ethanol.
After coming up with the idea five years ago (2015) and securing funding from the Scottish government, the business has been producing 500,000 litres of biofuel each year. This biofuel can be used to power vehicles and machinery used in industry.
Three years ago, scientists from the University of Bristol’s School of Chemistry were making similar achievements. They learned how to turn alcohol into butanol to replace petrol.
Researchers from the University of Valladolid (Spain) also managed to produce a type of butanol made from spent grains. From experimenting with other plants, such as beets, to make biofuel, it was discovered they could also use spent grains.
With a rise in the types of beer and small businesses specialising in craft beers, ideas on how to best put the waste to good use are needed.
How sustainable is biofuel?
While not always thought of as being completely sustainable, as it still produces carbon dioxide, how eco-friendly is biofuel?
Well, as it comes from plants, the carbon dioxide absorbed from these plants during the growing process is said to offset the CO2 produced from the end result of using biofuel. In this way, it’s said to be less harmful to the environment. Although it’s not the most sustainable and there is still a way to go, it’s a good start towards helping the planet.
Some work is being developed around making grains into eco-friendly cutlery, run by the Friendly Knife project. The knives and forks are being designed so they are fully biodegradable and compostable after use. This is done by mixing the grains, at a very high temperature, which can then be moulded into cutlery.
Many types of cutlery can only be used once and are not biodegradable afterward, as they are made with a small element of plastic. The project is in its early stages, with different types still being made to see which is the most effective.
The incredible innovative ideas coming out of how to put waste to good use reflect a long-overdue sustainable future. Utilising spent grains in a variety of ways, with more to be developed in the future, can only help to make beer production more conducive to an environmentally-friendly way of life.
