Green Beer, part 3
Waste Not Want Not
November 11, 2004 Written by
Last week we looked at the materials needed to deliver a tasty beer to your glass. This week we delve into the materials used in the brewing process itself, specifically the stuff that ends up leaving the brewery as waste. This includes spent grains, yeast, hops and wastewater, and it represents not only waste materials but also wasted energy as well. The energy in waste typically receives less attention than the energy required by manufacturing processes, but it is an important part of a holistic view of the brewing process. Peter Coors, CEO of Coors Brewing Company, notes the importance of waste reduction by saying, "Find pollution or waste and you’ve found something you have paid for but can’t sell - you’ve found inefficiency."
According to Gunter Pauli of Zero Emissions Research Institute (ZERI), up to 92% of the ingredients used in brewing ultimately become waste. One of the goals of ZERI is to channel all of a brewery’s waste product outputs, into inputs for other industries. I will also discuss this further when I profile Storm Brewing in Newfoundland where they are striving to employ ZERI principles. If you are eager to learn more now, you can read more at <a href=" http://www.zeri.org">www.zeri.org.
Grains and Malt and Happy Cows
A large portion of brewing waste is made up of spent grains - the malt and grains leftover after the sugars have been extracted in the brewing process. Spent grain is about 70% fiber and it is typically sold to farmers for cattle feed in North America, where farms and cattle ranches can typically use as much spent grain as the breweries produce. Brewers can’t just use less grain since this is pretty much what makes up the beer, so finding ways to dispose of it is important.
Brewers have found innovative ways to use their spent grains over the years. At Miller Brewing spent grains are seen as an opportunity, and they have set up a by-products business to find new uses for its grain waste. Marketed under the Barley’s Best brand name, spent grains are sold to farmers and commercial bakeries as a fiber supplement. Anheuser-Busch similarly keeps its spent grains out of landfills by feeding most of it to dairy cows. In one year 1.76 million tons of spent grains fed more than 200,000 cows!
Old beer past its expiry date can also be mixed with animal feed and fed to livestock as well. In Alberta, Molson’s outdated brews were mixed with the regular cattle feed to create a porridge-like mixture. Each cow receives a daily ration of 10 pounds, or about 12 bottles worth of beer mixed with 40 pounds of feed. They don’t have to worry about the cows getting drunk though, since the cows’ complex stomach system breaks down the alcohol in beer, transforming it into food energy.
Farmers willing to cart away spent grains for free find that word quickly spreads amongst local breweries. A dairy outside of Cleveland, Ohio began collecting grain from Great Lakes Brewing Co., and soon found itself collecting enough spent grains from local breweries to warrant the purchase of a small dump truck to help with pick up. According to their website, Great Lakes currently has partnerships providing spent grain to producers of organic beef, mushrooms and produce, and are researching the idea of locally grown hops.
In Ontario, Black Oak Brewing and Cameron’s Brewing in Oakville have their spent grain picked up by a local dairy farmer providing approximately 5% of his total feed needs. John Graham of Church Key Brewing tells us that feeding his spent grains to local dairy cattle while it is still warm can actually increase milk production in cows accustomed to a cold diet, which he attributes to warm happy cows.
Speaking of happy cows, the gourmets among us probably know that the cows used to make the world renowned Kobe Beef from Japan are fed a diet of beer, massaged, and brushed down with sake. The cattle are fed beer during the summer months to stimulate their appetite. Apparently the interaction of fat cover, temperature and humidity during the summer depresses feed intake.
Rudolph The Red Nosed Grain-Deer
Isolation can also be a factor in disposing of spent grain. Breweries in Alaska for example face the potential double whammy of having to first import grains to brew with, and then pay again to export the spent grains. Brewers in Anchorage were happy when a local farmer began collecting their spent grains and feeding almost a ton of it a day to his reindeer.
"Reindeer love the stuff, and tolerate it well," he says. "Some of it comes in large garbage cans and it freezes. We just haul it out there frozen, turn it upside down, and they eat it like a reindeer-sicle." Midnight Sun Brewing Company was paying to have the grains shipped off to a composting facility prior to the introduction of the reindeer farm, and they are currently sending their grains to a local hog farmer.
Alaskan Brewing in the coastal town of Juneau is not so lucky. Without road connections to the lower 48 states, everything comes and goes by water or air. They have to have their spent grain dried, packaged and shipped south by barge where it is fed to Washington livestock or used as compost. To save on shipping costs on the barge the brewery installed a grain drying system, the first craft brewery in the country to do so. Dry grain weighs less and is therefore cheaper to ship. To save on heating fuel costs for drying the grain, their grain drier burns about half of the dry grain produced to make more heat for drying. The grain drier uses half heating oil and half dried grain, reducing the brewery’s need for fossil fuels. Other means of local disposal are limited but include donating grains to local community gardens, composting projects and a local manufacturer who makes pet treats for cats and dogs. Alaskan Brewing was also the first craft brewery in the US to install a CO2 recovery system, which has allowed them to be CO2 self sufficient for the last three years.
For more details on brewing in Alaska see <a href=" http://www.anchoragepress.com/archives/document01cf.html"> www.achoragepress.com
In areas without large livestock industries, spent grain may end up in landfills, often the most economic disposal method available. While spent grain contributes healthy biomass to landfills, it can be used more efficiently as compost for farming, particularly mushroom cultivation. (I will discuss two breweries that make use of grain in this manner – Great Lakes and Storm Brewing – in later weeks.) Alternate means of spent grain disposal include using them as filler in pet food, or even people food. Many brewpubs offer spent grain bread on their menu, and under the ZERI model this is an important means of creating extra income for the brewer. (Not to mention tasty!)
Fun with Science
There some to have been a large number of scientific studies on uses for spent grains and other brewery wastes around the world.
Researchers in Japan have investigated the possibility of direct conversion of spent grains to gas. A reactor was used to convert the spent grain to carbon dioxide, methane and hydrogen gas. The gas can then be used as a fuel cell energy source.
In China, Foster’s Tien Giang has found an innovative way to protect local crops against fruit fly infestations by utilizing brewery yeast waste to process fruit fly bait. The process benefits farmers by increasing their crop yields, but also finds a beneficial for the brewery waste.
Polish researchers have experimented with using the protein from spent grains as a cultivation medium for studying microorganisms in soil samples. Their studies show that the spent grain medium allows the isolation of actinobacteria, especially Streptomyces, and enhances the sporulation. (I have to confess – I am still a little fuzzy on what exactly that means even after having it explained to me by a microbiologist, but it sounds pretty cool.)
Still to Come
Well, it seems I had more to say about the myriad of uses for spent grain that I had anticipated, so I am going to hold off on talking about wastewater until next time. As always I appreciate comments and questions so keep that beermail coming!
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"Reindeer love the stuff, and tolerate it well," he says. "Some of it comes in large garbage cans and it freezes. We just haul it out there frozen, turn it upside down, and they eat it like a reindeer-sicle."
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