Grow-your-own mushroom kits make great school projects, says Back to the Roots co-founder Nikhil Arora (far right).

RODALE NEWS, EMMAUS, PA—Several years ago, while studying business and investment banking in college, Alejandro Velez, now 23, and Nikhil Arora, 24, started experimenting with growing mushrooms in a University of California–Berkeley, frat house. (Wait! It's not what you think!) The two weren't previously acquaintances, but a random fact professed in passing by a professor—the fact that you can grow mushrooms in a sustainable way using coffee grounds—sparked such interest in the two young men that they decided to team up to try to make an urban farming business out of manufacturing and selling grow-it-at-home mushroom kits. (The 'shroom of choice? Oyster—this type grows fast, in just 10 days.)

Flash-forward two years, and the size of Velez's and Arora's business, Back to the Roots, is spawning major interest among investors and backyard gardeners alike. Some Whole Foods stores now carry the Back to the Roots mushroom kits, a product that Rodale.com named among the best in show at Natural Products Expo West in Anaheim, back in March. "We had no background in food or agriculture, let alone mushrooms," explains Arora. Still, the two perfected the art and are now receiving major accolades for their concept; awards include the 2011 MillerCoors Urban Entrepreneurs Series Business Plan Competition top prize and 2010 Busines Week Top 25 Social Entrepreneurs, and they are winners of the 2009 UC Berkeley Social Venture Competition.

The mushroom kit project, which started off in a 300-square foot-fraternity house kitchen, now inhabits a 10,000-square-foot facility employing 12 in West Oakland, Cal. "We're scaling up," cofounder Arora says. Still, Back to the Roots isn't forgetting its roots—the mission of sustainability. Even with production of the mushroom kits ramping up, the business is still sourcing all of its spent coffee grounds from a local coffee company, Peet's Coffee & Tea, in Oakland. Back to the Roots anticipates diverting 1 million pounds of previously landfill-bound coffee grounds for use in the kits.

"We're creating something positive and useful out of what was being thrown away; but beyond the product, it's creating livelihoods, too," Arora says.

Keep reading to find out how you can get a 10% discount if you order a mushroom kit.