Distillery Upcycles Spent Coffee Grounds for Liqueur

Getting to the point of fermenting coffee grounds without additional sugar—which meant breaking down barriers to access the naturally occurring sugars in the grounds—required significant additional research and trials. Once they could break down the barriers to ferment the coffee grounds, the process of figuring out how to commercially produce the liqueur began, presenting a different set of challenges.

The first step was collecting used coffee grounds. “We’ve got a partnership with a waste transfer company called Recorra,” says Murray & Yeatman CEO Rob Murray. “They have a bespoke coffee ground collection, if you think of it that way. So, all the coffee shops in the local area.”

Murray says the local shops are onboard with the idea, and one was particularly eager to join in because they had also made a commitment to the environment. The distillers then must ensure that no foreign matter that may have gotten mixed in during the collection gets included in the processing portion, such as used coffee filters.

“Having to have designed sieving machinery was an interesting ask, because when you’re looking at the laboratory size of things when doing test samples, it’s all very easy,” says Murray. “But when we have collapsable bulk containers and you’ve got a ton [of grounds] being delivered in one of those, then suddenly you start realizing the problems.”

The hydrolysis trials to determine how to get the right yield of alcohol was a time-consuming process that resulted in several utter failures. Further, the question of how to move the product around before the grounds had been fully broken down was a trial itself.

“It still has that grit element, and trying to pump it and trying to move it was a nightmare,” says Murray. “We have lots of pumps here, we’re a distillery, but actually finding something that could do it [was a challenge]. We ended up having to speak to different specialists without telling them what it was, and without giving too much away. I started just describing it as ‘mashed potato’ to people for the longest time. It was about the only way that you can explain what it was.”

Overcoming the Challenges of Upscaling

Realizzato is intended to be a sustainable product from its ingredients and production through to the packaging.Image courtesy of Murray & Yeatman DistilleryAs Murray & Yeatman looks to upscale the process from 1,000-liter batches up to as much as 6,000-liter batches, the question of how to move the liquid becomes more urgent. While the grounds are heavy enough that they typically stay to the bottom and there are filters in place to prevent their transfer from one stage to the next, there’s still the chance that some particulate will get through. It’s not so much of an issue now, but it will be as the company upscales.

“At the moment, our still is modular. If we need to really get inside it, we can take every bit off,” says Murray. “But if you've got a 10,000-liter still, that’s not possible. And while they’re clean in place, there’s still the maintenance of it. I think that's going to be the next hurdle.”

Murray & Yeatman is also looking at rapidly cooling the Realizzato. The heat of the liqueur at the end of the process is approximately 100°C, and the amount of time it takes to cool naturally was unexpected. The company can allow that process happen on its own for now, but that won’t be possible as production continues to scale. With that in mind, it’s another obstacle that needs to be overcome.

Currently bottled in recycled glass and labeled with recycled paper, the distillery is exploring the idea of repurposing grounds as a stopper for the bottles. The company is also trying to find a way to power its process using residuals of the distilled grounds.

Overcoming the initial obstacles—and the ones to come—is beyond more than one individual, according to Murray. “It's a team effort at the end of the day, no matter who you are for this, especially when it comes to the sustainability part,” says Murray. “We're all here trying to make this place—this world, this globe, this earth—a cleaner place. If we can, it’d be nice to leave it nicer for the next generation. Without those people looking at the alternatives, we wouldn't have been able to find it ourselves. It took a lot of their knowledge, us learning from it, then adapting it and changing it to create our own. It took a team effort.”