Spent grains, spent wisely


For about five years, I’ve enjoyed the privilege of contributing to the Michigan Beer Guide. Recently, the publisher allowed me to unite two of my passions, great beer and living sustainably, in a series of columns. What follows is the first installment of this series, reprinted with the permission of the Michigan Beer Guide. Cheers!

In nature, everything that’s produced is eventually utilized; there is no “waste.” Yet depending on the methods employed and the handling of the by-products, the brewing process can be very wasteful. A large portion of the waste produced by brewing is spent grain, but spent grain is actually not garbage: it’s a resource.

After mashing and lautering, that grain may be “spent,” but it’s certainly not useless. This soggy mass, consisting mostly of the celluloid grain husks and unconverted compounds, can benefit commercial breweries, homebrewers, and every one in between.

Hopefully, if the brewing process is successful, most of the starch in the original malted grains is broken down into sugars. However, the spent grains retain valuable protein and fiber, making them a useful addition to livestock feed.

On a large scale, breweries may give away, trade or sell their grain for use as feed. Whether or not the brewery makes a profit, it’s better than paying for it to be hauled away and dumped into a landfill. Across Michigan, many breweries enjoy agreements with local farmers who raise livestock such as cattle, pigs, chickens and goats.

For example, Frankenmuth Brewery gives away their spent grain to a local dairy and sheep farmer. The farmer reports that his herds are fat and happy, and that they literally run along the fence after the truck as it pulls up, laden with spent grain. Grizzly Peak BC in Ann Arbor works with a farmer in Dundee who feeds it to his livestock.

“Zero spent grain goes to the dump at Schmohz,” explains Chas Thompson, brewer at Schmohz Brewery in Grand Rapids. “We have a relationship with a dairy farmer with a large herd. They come pick up the spent grain and bring back the barrels clean. For me, that’s enough.” This is just a small sampling of the numerous Michigan breweries that make use of their spent grains in this way.

On a smaller scale, homebrewers and homebrew clubs can employ this method of spent grain recycling. Various Michigan homebrew clubs dedicate their spent grains throughout the year to feeding one specific pig; the animal is later the main attraction at a club barbeque.

However, there are other uses of spent grain that are more efficient, both economically and ecologically. Of course, if your goal is to live as sustainably as possible, beef and pork won’t factor into your everyday diet, since it takes anywhere between five and 16 pounds of grain to produce one pound of animal flesh. But the case for making frequent vegetarian choices is another topic for another day (or another publication), so I’ll step off that soapbox for the moment and focus on the nutritional value of spent grain.

Spent grains can be difficult for animals to digest, resulting in indigestion and flatulence, which adds methane gas to the atmosphere. Yet spent grain remains a valuable feed additive. A nutritional evaluation of spent grains used for animal feed, published in the journal “Plant Foods for Human Nutrition,” found that assorted spent grains contained roughly 20 percent crude protein and 50 percent dietary fiber. The grain contains essential amino acids, and some minerals such as magnesium, calcium, zinc and iron. However, a diet consisting solely of spent grains was not recommended; the study found that a diet of up to 25 percent spent grains is ideal for livestock.

So, outside of animal feed, how else to use all that spent grain? One way is to create delicious baked goods. Although recipes often call for only a fraction of the spent grain you’ll have on hand after brewing a batch of beer, there are recipes out there for everything from bread to crackers to pizza dough. Many recipes are available online.

This is an option for both homebrewers and commercial brewers. Look for spent grain as an ingredient next time you’re dining at a Michigan brewpub: The chefs at Frankenmuth are currently experimenting with a spent grain pizza crust, and the HopCat in Grand Rapids offers a house made spent grain flat bread.

Spent grain can be a key ingredient in great homemade treats for dogs and horses. One word of caution: do not use grain that came in contact with hops, as hops may be fatal to dogs.

Although it doesn’t have quite the mouth-watering allure of livestock feed or a baking ingredient, composting spent grain is an excellent option. Composting spent grain not only prevents organic solid waste from entering landfills, it also creates a product that helps restore depleted soil. If you have a compost pile, throw in your spent grain and your garden will love it! If you don’t have a compost heap, you can amend your garden’s soil directly with small amounts of spent grain. However, be prepared in this case for some strong aromatics.

How about some ‘shrooms? Spent grain may be used as a medium for growing organic shiitake and oyster mushrooms. One brewery already taking advantage of this fact is Great Lakes Brewing Company in our neighboring state of Ohio. They send spent grains to a local mushroom farm, and the resulting mushrooms feature in entrees at Great Lakes’ restaurant. You can find directions for cultivating your own mushrooms with spent grains at vermontmushrooms.com. As an added bonus, growing mushrooms on spent grains makes the grains more digestible to livestock and increases their protein content.

Worms also love spent grains. Thompson says a local vermiculturist loves giving Schmohz’s spent grains to his worms. Great Lakes is also on the forefront of this movement: their vermiculture compost bins produce natural fertilizer that’s used to nourish herbs and vegetables found on their menu.

In the commercial brewing world, putting spent grains to good use represents a bold move towards sustainable energy and self-sufficiency. The Zero Emissions Research and Initiatives (ZERI) put forth an innovate approach for commercial breweries. ZERI confirms the potential uses for spent grains in livestock feed, baked goods and growing mushrooms, then takes it a few steps further.

Waste from the spent grain-fed livestock may be mixed in a digester with brewery wastewater to generate biogas and a nutrient solution. The biogas can be used in the brewery or sold, and the nutrient solution feeds algae that in turn feed fish. The result is the utilization of all the nutrients, protein and fiber from the spent grains. If this sounds farfetched, consider the fact that a brewery in Tsumeb, Namibia already functions this way.

Breweries in the UK are also making strides toward sustainability. Scottish & Newcastle (S&N UK), the UK’s largest beer and cider company, is installing biomass plants in two of their breweries that will burn spent grain and locally-sourced woodchips. The steam and electricity generated by these combined heat and power (CHP) plants will be used for the breweries’ processes.

One of these CHP plants is at S&N UK’s Royal Brewery in Manchester, which produces many internationally known beers, including Foster’s Lager and Kronenbourg 1664. According to a Greenpeace UK case study, burning the 42,000 tons of spent grain this brewery produces each year will supply 60 percent of the site’s steam and almost all of their electricity. The result is an 87 percent reduction in fossil fuel emissions. S&N UK reports that the plant could reduce Foster’s entire carbon footprint by as much as 15 percent.

Homebrewing and choosing local craft brews are two very eco-conscious ways of enjoying your favorite beverage. And using spent grains is one more step toward living more sustainably. If you’re into social media, there’s an “I Use Spent Grain” group on Facebook where you can connect with others, share recipes and more. If you don’t homebrew, any local brewery will likely be happy to supply you with spent grain for your own endeavors. Drink local beer, use spent grains wisely, and be kind to the planet.