Marmite, a popular food spread developed from yeast at the Burton on Trent brewery in west-central England, is a by-product of brewing beer. The sticky brown food paste adopted the marketing slogan “love it or hate it,” hinting that its strong flavor is an acquired taste. For centuries, Burton on Trent brewed beer, but it has now gained another valuable brewing by-product in addition to Marmite—methane biogas. In 2008, the brewery built an anaerobic digester that converts the beer waste to methane, which is then burned to heat boilers to make beer.

More than twenty–five times more powerful than carbon dioxide, methane is an abundant greenhouse gas and thus has a significant impact on the world’s climate. China is the world’s largest emitter of methane. Methane is formed when organic matter, like food or beverage waste, is decomposed by microbes without oxygen through a natural process called anaerobic digestion. Methane biogas is natural gas and can be burned directly for heat or put through an engine to produce power.

China also has the largest beer market in the world, producing 4.6 billion liters per year, compared to the United States’ brewing 2.9 billion liters. In China, the United States, and all around the world, breweries are seeking ways to decrease their environmental footprint while increasing production and profits. Every step in the beer–making process generates waste. For every 1,000 tons of beer, about 150 tons of solid waste are produced as spent grains and waste yeast. Brewing is also energy intensive. The energy needed to produce, package, and distribute 15 barrels of beer could provide a U.S. household with electricity for 1 month.

Conservation as a Core Value

Brewers in both China and the United States face few special regulations or requirements for managing their waste, but wastewater treatment surcharge fees and hauling costs for disposal are high and increasing. Across the United States, breweries have found ways to convert their waste into a resource. Anaerobic digestion with methane capture reduces pollution, all the while cutting energy costs as a part of the core philosophy of environmental stewardship at breweries.

Magic Hat Brewery in Vermont, whose slogan is “saving the Earth, one beer at a time,” is converting waste hops, barley, and yeast into methane via a $4 million digester. Processing in the digester has reduced the brewery’s wastewater treatment bill by eliminating $600 per day in surcharges.

From its start in 1980, Sierra Nevada Brewing Company in Chico, California was a resource-conscious company. As a large craft brewer, recycling 99.5 percent of its materials, Sierra Nevada’s efforts are supported by the PG & E Climate Smart program, which purchases greenhouse gas emission reductions. Their anaerobic digester captures 2,265 m3 of methane—the equivalent of 13 barrels of oil—each day to power their boilers.

These are just two examples of U.S. breweries harnessing the power of turning waste into resource. In other states, such as Wisconsin, business-government partnerships are taking advantage of this energy opportunity as well. Starting in 2008, Gunderson Lutheran Health System in La Crosse, Wisconsin started to develop renewable energy projects with the goals of being energy independent and reducing harmful emissions linked to disease. In a unique partnership, and with the support of a statewide energy efficiency program called Focus on Energy, they are working with City Brewing Company to convert brewery waste to biogas to electricity.

Anheuser-Busch is recovering biogas at 10 of its 12 U.S. breweries, making the company the largest operator of anaerobic digesters in the world. In 2008, their Merrimack Brewery in New Hampshire received the Governor’s Award for Pollution Prevention. Biogas generated at their Fairfield, California plant supplies 15 percent of the brewery’s energy needs.

China’s Commitment to Methane Capture

The brewing industry serves as a role model for other food and beverage processors. Methane capture is one innovative way they can increase energy efficiency, recycle their waste products, and reduce greenhouse gases. Brewers capturing methane can be a win for breweries and for the environment.