Coffee Grounds Compost

Change your Garden or Change the World

From here it looks like coffee grounds compost can not only give your garden a boost, it can change the world.

People like me who love coffee and drink it daily can easily acquire a big bowl of coffee grounds. But the real gold is probably at your local coffee shop. There, a small shop can easily fill a five gallon bucket with grounds everyday. If these get tossed in the landfill it is really a shame. They are just too darn valuable to waste like that.

Used coffee grounds have about 2% nitrogen. Their C/N, carbon nitrogen ratio, is 20, or about 20 parts carbon to one part nitrogen. While coffee as a drink is acidic, the spent coffee grounds are not. The water leaches out the acidity leaving the grounds a neutral 6.5 to 6.8 pH. Coffee grounds compost makes an excellent addition to your garden.

What Can You Do with Used Coffee Grounds

Composting Coffee Grounds

When you make coffee grounds compost you need to think of the coffee grounds as a compost green. Their C/N ratio of 20 qualifies them as a good nitrogen source for your compost even though they are actually brown in color.

Compost coffee grounds with the coffee filters. The filters, being paper, qualify as a brown, or carbon source for the compost. Don't worry too much about bleached paper filters. Compost organisms are easily up to the task of breaking down any tiny amounts of bleach residue that may be on the filters.

You'll also want to add other things to the compost - most browns such as leaves or shredded paper, and some additional varied vegetable waste. Aim for no more than 25% of your compost being coffee grounds.

Coffee grounds have the same C/N as some manures. Both manure and coffee grounds will heat up your compost pile, however, with coffee grounds it seems the heat has staying power. One report says that temperatures of 130 to 150 F were maintained for about two days with manure and about two weeks with the coffee grounds.

If you're a lazy composter - as I often am - you can just toss your grounds on top of the soil. Over the course of a month or so they will break down in the same way sheet composting works.

Feed Your Worms Coffee Grounds

I've often wondered whether the coffee mad worms of Men in Black were inspired by the food preferences of someone's worm bin. Worms do seem to love the coffee.

Just give them a balanced diet - and make sure they have enough bedding and you'll have awesome worm castings, coffee grounds compost, in short order.

Mulch with Coffee Grounds

This is kind of like sheet composting when you just lay a layer of coffee grounds as mulch for your plants. There may be some problems, not with acidity, but possibly with the caffeine residues in the spent grounds. These caffeine residues break down completely in compost. A thin layer will be fine, as soon the soil organisms will get to work and essentially compost the coffee.

Some people have tried mixing uncomposted coffee grounds directly into the soil so that the coffee is about 25% of the mix. This may cause your plants to suffer for a while until the soil organisms get to work and break the coffee down. No big deal in the big picture as within a couple of months all will heal.

So, if you are mulching - use only thin layers of coffee at a time.

Grow Your Own Gourmet Mushrooms on Used Coffee Grounds

I was entranced by the possibility of composting coffee grounds while growing an edible, gourmet crop. I ordered an oyster mushroom growing kit from Fungi Perfecti and today it looks like the mycelium has colonized the coffee grounds my friend Paula gave me from the coffee shop she manages, Collossi's. My bucket now shows a film of white mycelium. When they start to fruit I'll update with a photo.

Start a Business - BTTR Ventures

BTTR is the business begun by two young business school grads from University of California - Berkeley. In a nutshell the two men collect around three thousand pounds of used coffee grounds a week from the town coffee shops. They then seed them with Oyster mushroom spore and grow a crop of gourmet mushrooms. Once the crop is harvested the coffee grounds are fully composted and ready to be used in local parks and on area farms.

Change the World - Breaking New Grounds in Louisville KY

For Gary Heine and Mike Mays of Louisville Kentucky changing the world started with business. They were looking for a way to make a living while making a contribution.

They started what is now a small chain of coffee shops, roasting fair trade coffee beans and serving fair trade coffee. Heine Brothers Coffee holds that just by drinking a cup of fair trade coffee you help farmers in coffee growing lands earn living wages and grow coffee in a sustainable way.

In and of itself this is a great thing. But these men wanted to take it to the limit and so started worm composting and later regular composting of the mountains of used coffee grounds and filters they were starting to generate. More food waste was added to balance the piles, more partners were joining the work.

Naturally this led to growing food and to an organization called Breaking New Grounds. Community gardens and food are the ultimate results so far and it all started with two guys and a cup of coffee.

Check out part 1 and 2 of this You Tube Video.

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