Using Coffee Grounds In Compost

It’s estimated that over two billion cups of coffee are consumed around the world each and every day. And that’s an enormous volume of grounds which are used and then tossed in the trash. By using coffee grounds in compost instead, you can help cut down on waste and provide a boost to your garden as well.

Are Coffee Grounds Green Or Brown Compost?

Compost needs both “green,” and “brown,” materials. (Typically you want two to three times the amount of green to brown.) “Green,” materials are those which are high in nitrogen while “brown,” materials are high in carbon.

Despite their brown color, coffee grounds are considered a green compost material. They are actually very nitrogen-rich and have a nitrogen to carbon ratio of around twenty to one. This is high enough that it makes them a suitable alternative to fresh grass clippings, which are a favorite nitrogen booster of many long-time composting gardeners.

How To Add Coffee Grounds To Compost

There’s nothing special you have to do when adding your coffee grounds to your compost. Simply toss them right in. However, you may want to immediately follow them up with some “brown,” materials to ensure your pile or bin stays balanced. While new coffee grounds are considered acidic, this is not the case once they have been used to make coffee.

The pH of used coffee grounds can actually range from slightly alkaline, to neutral, or slightly acidic. These levels can also change as the coffee decomposes in the compost over time.

Because of this, when adding coffee grounds in the compost, you’ll want to make sure you don’t put in too much. While adding very small amounts can be beneficial, a good rule of thumb is to keep grounds at between ten to twenty percent of your entire compost pile. Anything over that could cause harm rather than helping.

Benefits To Compost

Other than adding nitrogen to compost coffee grounds along with other kitchen scraps such as orange peels, eggshells, and used tea bags, help to add a diversity of organic materials to your compost. And that diversity helps to support a wide range of helpful microorganisms.

Grounds can also be a source of food for larger decomposers such as earthworms. (For this reason, grounds are also often added to worm farms and bins.) Once digested the worms turn the grounds into nutrients such as carbon and nitrogen which are released back into your compost

As worms feed on the grounds they are often pulled deeper down into the pile. And this can help to improve the overall structure of the compost. As the coffee grounds gradually decompose they also produce important components of humus. Interestingly the bacteria and fungi which form on decomposing grounds help compost too. They actually prevent harmful molds, bacteria, and fungi from becoming established.

Can You Compost Coffee Filters?

Many gardeners wonder if they can also compost coffee filters as well. And the answer is yes! Paper coffee filters can be composted. Despite being made from natural materials there is actually no way to recycle them. So if they aren’t composted they are sure to end up taking up space in your local landfill. The same goes for paper towels, paper napkins, and uncoated paper plates too. So don’t forget to add these items to your compost bin or pile as well.

Save That Coffee Can

If your coffee comes in a can, you can re-use it to help you with your composting effort as well. Cans are ideal for storing not just grounds, but also other kitchen scraps and items that you collect over the course of the day which will be composted. Their tight-fitting lid will be sure to keep any smells contained. And you can even place your can right on your kitchen counter without it looking out of place or anyone suspecting what you’re keeping inside.

Scoring Free Coffee Grounds For Compost

If you’re not a coffee drinker yourself, or you’d simply like some extra grounds, there are a few options. You definitely don’t have to buy used coffee grounds, because with a small amount of effort you can almost always get them for free. Local coffee shops can be a great source of free grounds. Just be sure to talk to the owner or manager before you show up with a bucket in hand.

You’ll want to find out what days and times they typically get rid of their used coffee grounds that way you don’t end up wasting time. This can also help you to get to the grounds first before any other competing composters do and will minimize wasted time. Some coffee shops may even leave grounds out either inside or outside of the store for anyone who wants them.

And for those who don’t mind getting dirty, “dumpster diving,” is always an option. You may also want to think about asking for used grounds at less obvious choices such as supermarkets and convention centers. If you work in an office, break rooms and cafeterias can also offer large amounts of grounds regularly too.

By using coffee grounds in compost you’ll be sure to enhance its quality. And that means when your compost is added to your garden your plants will reap the benefits of more nutrients, better soil structure, organic material, and helpful microorganisms.

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