I got my first job when I was about 4 years old, helping my grandmother's friend Tony Pasteta in his garden. My job was a simple one -- I brought him the coffee his wife Luisa made for him and protected the garden from gnomes while he sat on a bench and drank it, then carried his empty cup to the compost heap in the corner and emptied the dregs and grounds onto it. For that, I got a shiny nickel that I could spend at the corner store for a Popsicle. Tony always left one good gulp of coffee in the cup -- for the gnomes, he said, because even a gnome shouldn't have to drink American coffee. And if you give the gnomes good coffee, he said, they make good dirt for the tomatoes.
Tony may have been embroidering the story a bit for my impressionable 4-year-old ears, but he was right about one important thing -- coffee grounds go very nicely in compost and do a great job as a soil amendment for acid-loving plants, tomatoes and roses among them. Most people like to trace the journey of the coffee bean from plant to cup. If you follow the trail beyond the cup, though, you'll find that the vast majority of spent coffee grounds end up in landfills, where they do no one any good.
As a greenie from way back and a dyed-in-the-wool coffee lover, it's always bothered me that people just throw their used coffee grounds away when they're so useful in so many ways. And I'm apparently not the only one. Here's a handful of some of the uses that others have for spent coffee grounds, collected from around the web and around town over the past few years.
- As noted,spent coffee grounds make a great compost addition and soil additive. In many cities, your local coffee shop will happily hand over a bucket of grounds if you ask them. In my home town, a couple of coffee shops have partnerships with community gardens that regularly pick up the used grounds to add to their compost.
- People are willing to pony up big bucks for bars of coffee soap and coffee body wash. My grandmother used to make her own coffee handwash by adding the grounds from one moka pot of coffee to melted soap scraps and pouring it into a covered hand cream jar. The grounds do a great job of exfoliating dead skin -- and they absorb odors. I make it with plain glycerin soap and used coffee grounds, and use it to wash my hands after handling fish, onions or garlic. My hands feel great and they don't stink.
- A couple of years ago, chemical engineers at the University of Nevada, Reno came up with a process to turn used coffee grounds into biodiesel fuel. They start by drying the used grounds in an oven, then use a chemical process to extract the oil from the coffee grounds. The process may be efficient, but it's not terribly practical, according to scientists. Because coffee grounds are only about 15% oil, it takes about 50 gallons of used coffee grounds to make one gallon of biodiesel fuel. Still, it's a pretty cool idea -- and every little bit helps.
- Taiwanese textile company, Singtex, has won awards for its S.Cafe fabric, a high-performance sports/outdoors textile that's made with used coffee grounds. The chemists at Singtex devised a way to "empty" the structure of the coffee grounds and leave the framework in place. S.Cafe fabric neutralizes odors -- including body odors -- provides UV protection and dries fast, making it a natural for active, outdoor clothing. Big names in extreme and outdoor sports have already partnered with Singtex to produce clothes using S.Cafe -- you'll find shirts made from the coffee-impregnated fabric at Eastern Mountain Sports, New Balance and AUR Golf. The company says that the grounds from one medium cup of coffee can make enough fabric for two t-shirts -- and no, they don't smell like coffee.
- Coffee grounds are an age-old home remedy to repel slugs and other nasty pests from your garden, but the Charlotte-Douglas Airport takes things a step further. The airport's housekeeping manager was looking for a way to use the nearly 1 ton of coffee grounds put out by the airport's 6 Starbucks' stores every week when he ran across an article about coffee grounds repelling fire ants. Since the airport has a major problem with fire ants, he figured what the heck! At worst, it wouldn't work. Since 2008, the airport has been spreading the used coffee grounds around runway and traffic lights, where staff used to have to fight off fire ants when doing maintenance work.The airport saves close to $800 a yearby recycling the grounds instead of hauling them off to a landfill.
I'm sure there are other ways to use up those used coffee grounds. What do you do with yours?