Spent Grain and its Potential

Cows Feeding

Cows eating spent grain

Water, hops, yeast, and barley: essential elements of beer. We talk nearly nonstop about hops here in the Pacific Northwest, and for good reason. The Yakima Valley growing region supplies 77% of America’s hops and exports two-thirds of their total product globally. But we tend to forget that the Northwest is also a fruitful agricultural center for barley. Washington state ranks fourth in the nation for total production, and the WSU Barley Breeding Program is an ongoing testament to a strong focus on development. Notably, wheat has also been bred at WSU for over a hundred years. It’s evident we have a strong local commitment to growing quality cereal grains. While only 4% of the barley grown here is destined for the malt house, the Washington Grain Commission estimates that most craft brewers use 3.4% more barley per pint than macro breweries. At 25 pounds (or more) dry malted grain needed per keg (that’s half a barrel; about 120 pints), this adds up quickly, especially for production craft breweries who might brew 20-90 barrels at a time, multiple times per week and/or day. After the mashing process, when all possible malt sugars are extracted and drained away, the hydrated malt is removed from the mash tun and disposed of in various ways. For obvious reasons, it can become extremely tedious and expensive to merely shovel this spent grain in the dumpster. Municipal waste retrieval has limits, even for large food and beverage production companies. And more importantly, spent grain still has value in other uses.


A good meal for chickens

Food and Animal Feed

Although the majority of the sweetness is drained and rinsed from the grain, a small amount remains along with a few other nutrients, a huge amount of fiber, a level of protein comparable to alfalfa, and importantly, far less starchy materials than unmalted, unconverted grain like raw barley, corn or oats. Essentially, spent grain still has food worth and can be consumed by humans and pets alike, baked into breads, cakes, pizza dough, dog biscuits, and other products. Chickens, ducks, geese, cows, and pigs also enjoy it as a portion of their diet (turkeys, apparently, are not fans). Turns out that humans enjoy chickens, ducks, cows and pigs as a portion of their diet as well. Indeed, many breweries send some or all of their spent grain to nearby farms, making a great connection for serving local meat products in associated restaurants or tasting rooms. Some breweries have even invested in their own farming ventures to supply their restaurant-side needs. It’s a wholesome, symbiotic full-circle type of reuse and waste limiting that makes wonderful sense to both craft brewing and farm communities.

Compost and Soil Amendment

Another obvious destination for spent grain is the compost pile, for personal gardens and commercial farm operations alike. Spent grain is a high-nitrogen material, and once mixed with a high-carbon material and/or bulkier substances such as wood chips for proper aeration, it composts very well. The benefits of a healthy compost application are endless, especially when you consider the resource conservation and reduced energy costs of using local productsmany farmers and gardeners purchase compost produced hundreds or thousands of miles from their growing sites, contributing to transportation-related emissions and higher costs. There have also been some successful initial studies on utilizing spent grain to help reduce soil erosion and aid in total water retention in dry or overly industrialized areas, a concept that seems contemporarily useful considering the effect of recent global droughts on agriculture.

Stone Soap

Stone Soap


Compost and animal feed are messy, sticky materials to handle, but luckily you could clean up with some spent grain soap afterward. Yes, you can include spent grain in soap, just like oats or any other gently exfoliating material. The Beer Can Soap Co. in San Diego uses the owners’ own spent grain from homebrewing to make their line of soaps, which are shaped in beer can tops for full effect. Or you could buy some Ruination IPA soap from EverAfter Naturals, which uses Stone Brewing’s Ruination IPA (and of course, spent grain) from the Stone Brewery in Escondido.

Mushroom Growing

Spent grain can also be used as a substrate for growing mushrooms on small or large scales. Fungi derive all their growth and energy potential from the biochemical decomposition of whatever medium their spores are inoculated upon, and as we already mentioned, spent grain composts readily. Certain mushrooms are more particular about their circumstances, but oyster mushrooms especially enjoy a landscape of spent grain. While most breweries would prefer to keep excess microbiological materials outside their walls, some are also venturing into cultivating mushrooms, usually in a sterile, separated space. Great Lakes Brewing Co. in Cleveland, Ohio is one such example.

AK beer

Alaskan Brewing’s “beer powered beer”

Fuel and Energy

On the energy side of things, Alaskan Brewing Co. has developed a unique “first-of-its-kind” steam boiler fueled by burning spent grain, reducing their overall use of oil for fuel by a whopping 65%, a big improvement for the state’s largest brewery. It was a hugely meaningful investment for the brewery, who had been drying and shipping their spent grain south often more than 2,000 miles to cattle farms in the Northwest for almost 20 years. “…we have a problem in Juneau,” they explain, “no cows!” (Apparently reindeer aren’t excited about spent grain either.) While most smaller breweries wouldn’t typically have the funds to buy such a boiler system (purportedly an $1.8M purchase), it certainly gives hope that alternative, better and sustainable options will be available in the future.

With the exponential rise in brewery openings in the US, appropriate destinations for brewing byproducts are becoming more and more necessary. Deschutes Brewery now hires a commodity group to manage the disposal and distribution of their spent grain (more than 11,000 tons annually). I expect more groups to arise and aid the craft brewing industry, especially for the larger regional companies. However they manage their byproducts, I look forward to witnessing the development of more innovative methods of reuse.