How Breweries Like Brooklyn Brewery Use their Leftover Grain

The first time I brewed my own batch of beer, I had every intention of using the leftover bag of grains that comes with it: I’d grind it into flour! Make bread with it! Oatmeal cookies! But as soon as I pulled the sopping-wet grain bag from my beer pot, I panicked.

This bag of grains is one of the first steps of brewing beer. It's steeped in a pot of hot water, which in turn takes on the flavors and sugars of the grains and turns the recognizable golden- to dark-brown color of beer. Once removed from the hot water, the grains themselves are still fully edible and nutrient-rich.

The recipes I found called for drying it in a low oven over several hours, but with a boiling pot of water on the stove, all three ovens in our office otherwise claimed by the test kitchen, and the responsibility of having my beer come out literally picture-perfect, I tossed the grains—all 18 ounces of them. Which got me thinking, what do breweries, who sometimes produce thousands of gallons of beer every day, do with their grain byproduct (or spent grains, as they’re called)?

When I spoke with Garrett Oliver, the brewmaster at Brooklyn Brewery, he told me, “Depending on the weight from moisture, we’re probably looking at a good eight tons per day during the week of spent grain.” Eight tons!

Despite the enormous amount of byproduct—in the middle of a city, no less—Garrett said that they, and many breweries in the area, have a solution: They pass it along to farmers to use as pig and cattle feed. Garrett said of the grain, “It’s pumped into a tank in the brewery, and then a truck backs directly into the brewery to fill up, then distributes the [spent] grain to farmers. It’s a break-even situation for us—and it’s great feed. Not only does it [the spent grain] have plenty of cellulose, but is also packed with protein.”

Using this process, Garrett explained that most breweries are able to put their grain to good use. But what about homebrewers or breweries that don’t have access to a farm? This is where turning spent grain into food—for humans—comes in.

For larger breweries, turning grain into food is not cost-or time-efficient. Spent grain-based foods only require a small amount of the grains, and going through the extra step of processing and dehydrating the grains is taxing (and in some cases impossible) for many breweries. But drawing this direct cost-benefit analysis between cooking with spent grains and cost efficiency may be missing the bigger picture. Where using spent grains in food for people is most effective is in closing a gap in beer knowledge and encouraging a culture of less waste.

Garrett told me, “Craft beer is the hottest thing happening in [the beverage industry] by far—but people still have not the slightest idea what beer is. Using the grains in food ties it to the idea that beer's an agricultural product, rather than just thinking of it as coming from stainless steel vats.” And for homebrewers, he said, using the grains can “lead people in the direction of getting away from food waste.”

He elaborated, “It’s the same idea that if you’re making dinner and you have lamb chops leftover, you don’t throw the lamb bones out—you put them in a stock put tomorrow.” (For those paying attention, I atoned for my first batch of wasted spent grain by turning my second batch into bread.)

Where Garrett said he has a problem with putting grains into food is when it doesn’t actually enhance the food and instead becomes a gimmick. He said, “A lot of people now are using beer ingredients as a gimmick in food—and to me, that’s lazy and uninteresting.”

The spent-grain granola bars made by the company Regrained, in San Francisco, would likely be included in what Garrett refers to as a gimmick. The bars are labeled “Honey Almond IPA” and “Chocolate Coffee Stout,” despite the exclusion of both hops and any stout characteristics, respectively. The only commonality they share with beer is the grains, which taste fibrous, to be honest, and are hard to chew. But their mission is nonetheless similar to Garrett’s—to educate people about beer and keep grains out of compost bins—even if they miss the mark on taste.

Dan Kuzrock, Regrained’s co-founder, told me over the phone that while he admires the relationship breweries have with farmers, he and his business partner are “addressing the gap that exists in urban areas” where fuel and time costs can inhibit farmers from picking up grains. Granted, that gap may be small—Garrett said that even in a city as large as New York, “relatively few breweries actually discard their spent grain as garbage”—but Dan is doing what I was too busy and overwhelmed to do: Turning the spent grain into food.

If you’re interested in experimenting with spent grain, but don’t homebrew, the easiest way to find them is to go straight to the brewery. Garrett said, “We’re always happy to give it up, but make an appointment before dropping by so that we can make sure the grain you’re getting is fresh.” He added that most breweries would try to make accommodations.

To use spent grain—whether to educate a friend about beer or to experiment for yourself—lay your moist grain out to dehydrate in a low oven, around 200° F for about 7 hours, or until completely dried. From there, you can pulse the dried grains into flour or use them as you would oats.

Have you baked with spent grains? What do you think about foods with beer in them—gimmick or delicious invention? Tell us in the comments below!