(This appeared as my Spring 2007 Column in American Brewer)
According to Gunter Pauli of the Zero Waste Research Institute 92% of brewing ingredients are wasted. Most of the waste is spent grain that still has lots of useful protein and fiber. From a business perspective, that spent grain is potential revenue that most brewers are either giving away or paying to have removed as refuse. Why let that grain go down the drain when that mushy malt can be turned into money?
Feed Is for the Birds
By far the most common use of spent brewers grain is as animal feed, primarily for cattle, but also for pigs, goats, fish and just about any other livestock. In a 2003 survey of 45 breweries, 38 said their spent grain was used as animal feed, mostly for beef cattle and dairy cows. Some brewers, like Allagash, Deschutes, and Kalamazoo claim to fetch a small price for their grains, but most breweries give it away for free, which is certainly better than paying waste disposal fees. But cattle feed is neither economically nor ecologically the most efficient use of spent grain.

(Anderson Valley Brewing Company collecting spent grain.)
Cattle require as much as 20 pounds of grain per pound of beef, and need 2,600 gallons of water to produce a single serving. A new United Nations study (Livestock’s Long Shadow, December, 2006) surveys the ecological damage done by livestock, including sheep, chickens, pigs, goats and cattle. According to the report, the world’s rapidly growing herds of cattle are the greatest threat to the climate, forests, and wildlife, and cause a host of other problems too, from acid rain to the introduction of alien species, from producing deserts to creating dead zones in the oceans, from poisoning rivers and drinking water to destroying coral reefs. The world’s 1.5 billion cattle produce 18 per cent of the greenhouse gases that cause global warming. Fuel to produce fertilizer to grow feed, to produce meat and to transport it – and clearing vegetation for grazing – produces 9 per cent of all emissions of carbon dioxide, the most common greenhouse gas. Oh, and boy do they stink – cow flatulence and manure emit more than one third of emissions of methane, which warms the world 20 times faster than carbon dioxide.
As usual though, small brewers are among those at the vanguard of a trend that is addressing these problems. Many brewpubs now feature the very meat that was raised on the brewery’s spent grain, often times raised according to organic methods of husbandry, thereby supporting local sustainability and limiting some of the environmental woes caused by global, industrial livestock. But while reciprocity between local brewers and cattle farmers may be better than sending grains to landfill, there are still plenty of good reasons to seek more efficient and creative ways to reuse brewers draff.
Compost Is the Most
According to the International Soil Conservation Organization, 65% of the world’s soil is degraded. Directly staunching the causes of topsoil loss (poor agriculture and forestry practices) may be difficult for brewers, but compost is an effective and accessible way they can help revive soil health. Schlafly Beer in St. Louis used money from a Missouri Department of Natural Resources grant to research various uses for spent grain and found that compost was the best option. Another grant, from the County Solid Waste department, got their compost system up and running. A local vendor packages and sells most of the finished product, and a portion is also used on the brewery’s own half-acre kitchen garden.

(Patrick Conway, co-owner of Great Lakes Brewing in Cleveland, gets his hands dirty in one of the brewery’s vermiculture compost bins.)
Carrie Farthman, at Schlafly, raves about the new-found life for their brewery waste, “composting spent grain not only cuts down on organic solid waste in our local landfill, but it creates a product of great use to local businesses and the well being of the land. We are thrilled at the opportunity to treat the byproducts of our primary production process as a valuable asset to our community, economy and environment.”
Turn on to Some ‘Shrooms
Spent grain compost can also be used as a growing medium for mushrooms. Schlafly is hoping to use another grant to renovate storage areas at their Bottleworks to create incubation and fruiting rooms that will use spent grains and spent yeast to grow oyster mushrooms they will serve at their two restaurants. Likewise, Great Lakes Brewing Co. in Cleveland provides spent grain and scrap paper to their partners at Killbuck Farms to grow organic shitake and oyster mushrooms that are used in entrees at their pub restaurant.
Bakin’ the Barley Goods
Spent grains also morph into all manner of delicious baked goods. Glenn Brady, brewmaster at Silver Gulch Brewing and Bottling Co. in Fox, Alaska harvests draff from the middle of the grain load in the lauter tun right after the sparge in a technique he says avoids teig (the pasty proteins that settle on top of the sparge grains) and gets only still-hot grain, which he says reduces the chance of unwelcome infections taking up residence before the grain goes to its intended use as an addition to his homemade breads.
The historic Frankenmuth Brewery in Michigan serves their chili in a spent grain “bread bowl”. Granite Restaurant and Brewery in Toronto matches jalapeno spent grain bread with their Best Bitter as part of a prix fixe beer dinner menu. The bruschetta served at Hales Ales in Seattle is spent grain crostini topped with fresh mozzarella, vine-ripe tomatoes, and fresh basil, drizzled with balsamic reduction vinegar. And if you think that sounds good as a first course, how about following it up with their slow-smoked pork shoulder in Hale’s Stout with barbecue sauce served on a spent grain roll. But it might be a toss-up between that and their Pacific Rockfish breaded and pan fried, and served with tartar sauce, lettuce, tomato, and onion on a spent grain baguette. Then there is Firestone Walker, World Beer Cup Champion Brewery and Brewmaster two years running in 2005 and 2006, whose ingredients reflect their commitment to locally and regionally grown ingredients, including the spent grains used to craft their pizza dough.
Dog Biscuits, Ethanol and Bio-Plastics
Looking for something a little more unusual than bread? Try drying and milling spent grain into flour and baking it into your favorite cookies. One brewery rolls it on to their own homemade dog biscuits. The possibilities in the bakery are virtually endless, but scientific laboratories have been creating some even more unexpected products. In Japan, the Akita Research Institute of Food and Brewing has developed a new technology that drastically reduces the cost of producing polylactic acid, the spent grain-derived basis from which they are making biodegradable plastics. In Akita Prefecture, one of Japan’s major agricultural areas, most food processing waste is incinerated or discarded in landfills, so the new technology is expected to be an economic as well as an environmental boon.
Coors Brewing has been producing another petroleum alternative with their spent grain, one that brewers have always made in low concentrations, ethanol. But this ethanol is made from waste grains and spilled beer and being sold as commercial fuel-ethanol. In 2005, Coors and project partner Merrick & Company, opened their second plant together in attempts to meet growing demand for the product.
“We’ve basically taken a waste stream and turned it into a revenue stream,” says Steven Wagner, the Merrick vice president who helps lead the Coors ethanol project. The ethanol is sold under a contract with Valero Energy Corp., which distributes the beer-ethanol to Diamond Shamrock stations around Denver. With federal regulations mandating ethanol fuel use and bio-based product procurement, fuel production and bio-plastics may soon become the most attractive option for brewers everywhere.