Protein seems to be the macronutrient du jour, with Cargill’s 2025 Protein Profile showing that 61% of people increased their protein intake in 2024, up from 48% in 2019. That protein seems to be coming from all over, from meats to vegetables and even your morning coffeeand soon, it might come from your beer, too.

In 2024, food science researcher Toktam Farjami published a study in Food Hydrocolloidsdemonstrating that proteins extracted from brewer’s spent grain — the most significant byproduct of beer production — can be used to encapsulate fish oil.

Farjami shared with Phys.org in September that this is a valuable source of protein with excellent properties. She noted that trends in the food industry have shifted toward the “utilization of plant resources due to environmental concerns and growing consumer demands for healthier and more ethically sourced food products.” So, replacing animal proteins often used in encapsulating fish oils with plant proteins like those found in spent grain can offer “enhanced sustainability, greater availability, reduced allergenicity, lower cost, and wider consumer acceptance among vegetarians and vegans.”

To understand how this spent grain could be put to work, Farjami first extracted proteins from the byproduct. She then used these proteins to develop several versions of protective coatings, some left as-is and others treated with citric acid, a common food additive that helps proteins bind together. Next, she blended these protein coatings with cod liver oil and water to create emulsions, experimenting with the acidity of each mixture. She then spray-dried the emulsions into a fine powder, creating microcapsules filled with oil. Finally, she tested each version side by side to evaluate how effectively they trapped the fish oil, and, most importantly, how long the oil remained fresh.

The good news is, the results showed that all the spent grain capsules did a solid job of locking in the fish oil, regardless of how they were prepared. However, some versions stood out as clear winners. Farjami found that the capsules made at a lower pH and crossed with citric acid held the oil most tightly and slowed spoilage the best. Even after 15 days in warm storage, the oil remained stable. Compared to the industry-standard starch capsules, the spent grain versions performed better, proving that spent grain is far from food waste.

“In the future, we must make far better use of our resources than we do today,” Professor Eva Falch, Farjami’s supervisor, shared with Phys.org. “This requires not only technological research, but also insight into raw materials, market potential, and consumer behavior. That’s why research like this is so important.” And, as Falch pointed out, it offers a fantastic secondary revenue stream for brewers who produce 39 million tons of spent grain annually, adding, “These are the kinds of interdisciplinary innovations we need to build the sustainable food systems of the future.” We’ll drink to that.