At first glance, spent grains from breweries seem like an afterthought. Those leftover heaps of damp barley, which get stripped of their sugars during beer-making, don’t sound all that appealing to the average person. However, Ovissipour’s lab saw potential and found a way to give leftover barley a new life.

“There’s still a significant amount of protein left in these grains,” he said. “The trick is making it ready for human digestion.”

The team uses a two-step fermentation process to transform the leftover grains, which they received from collaborating local breweries.

First, they add fungi to break down the grains, making the protein within them digestible by humans. Then, they incorporated spent coffee grounds, an abundant waste product that the lab received from local coffee shops — and from their own coffee maker, which adds to both the nutritional value and flavor of the final product.

“Fermented coffee takes on a rich, chocolate-like flavor,” Ovissipour said. “It’s a natural way to add depth and sweetness without adding in chocolate, helping with both flavor and nutrition.”

Finally, after mixing in some nuts, the result is a chocolatey protein bar that serves as the perfect example of fermentation’s ability to unlock the potential going unused in our food system.