Will Coffee Filters Compost?

Perhaps you just finished brewing a strong cup of coffee to kick off a good day. As you’re cleaning up your coffee-making setup, you notice the coffee filters. Perhaps you begin to notice how many filters you go through every year, especially if you consume coffee daily (or several times per day). 

You probably toss the filter into the trash without a second thought. But now that you noticed, you’re starting to wonder if there’s a better way to dispose of these filters. Can you compost them? If not, what should you do with used coffee filters? Let’s find out. 

What Kinds Of Coffee Filters Are There?

Before we answer the main question, we need to address the variation in coffee filter types. Some of these filters are easily compostable, while others aren’t as simple to dispose of. Here are the main types of coffee filters available:

Paper Filters

Many generic coffee filters available on the market are made of thin, white paper. Manufacturers put the materials through a chemical bleaching process to achieve the white color. The purpose of the bleached filter is to ensure you know the filter is already used. 

Once the coffee is brewed, the filter becomes a brownish coffee color, indicating the filter is used. While these filters are technically compostable, the whitening process can lead to some chemicals leaching into your compost pile. 

If your goal is to keep your compost pile chemical-free, you might want to consider a different coffee filter option. 

Plastic Coated Filters

Some coffee filters feature a plastic lining inside the filter. The purpose of the plastic coating addition is to make the filter reusable. So, instead of tossing the filter in the trash, simply wash it and pop it back into your coffee pot. 

If you compost your coffee grounds, ensure you scrape the grounds out of the filter instead of tossing the whole thing in. Since there’s plastic in these coffee filters, you can’t put them in your compost. 

Unbleached Filters

Unbleached coffee filters mimic the design and thickness of bleached coffee filters, minus the chemical bleaching process. These filters are a natural brownish color due to the color of the wood pulp used to make the paper. 

Some folks prefer to steer clear of these filters, as the brown hue makes them appear used, but there’s not much difference between them and bleached filters. These filters are biodegradable and compostable. Given the lack of chemicals, these filters are perfect for you if you’re hoping to keep your compost pile more organic and strictly chemical-free. 

Chemex Filters

These filters are composed of paper and are thicker than standard paper coffee filters. The thicker design helps prevent grounds from passing through into the pot. Since they’re made of paper, these filters are compostable. 

These filters don’t contain bleach, so composting them isn’t a threat to the environment. No chemicals will be released into the environment, so composting these filters is perfectly fine. 

Can All Coffee Filters Be Composted?

Most coffee filters are perfectly safe for your compost pile. As long as they’re regular paper coffee filters, they can be a great addition to your compost pile. However, some coffee filters are treated with chemicals such as bleach. 

It makes sense, considering many paper coffee filters are white. Natural paper is usually brown, so bleaching is necessary to achieve a white coffee filter. There are more environmental ways to bleach paper, but many coffee filters are bleached with chemicals. 

So, if you’re trying to keep your compost pile entirely organic and free of chemicals and dyes, make sure your coffee filters are unbleached. 

How Long Do Coffee Filters Take To Decompose?

Once you add your coffee filters to your compost pile, it may take anywhere from six to eight months for each filter to decompose, which is a reasonable time frame for organic decomposition. 

However, if the filters dry out, the process will take even longer before the filters begin breaking down and decomposing. The process can be sped up if you use sealed compost bins (such as Lomi). It could take as little as one to four months for the filter to decompose fully. 

The faster decomposition rate is due to the more controlled environment in a sealed composting container. The seal ensures moisture levels stay at a solid level, which helps speed up the breakdown process to a faster rate. 

Can I Compost The Coffee Grounds With The Filter?

Having coffee every day or multiple times produces quite a few coffee grounds. However, instead of tossing the grounds in your garbage, add them to your compost pile. Avoid adding unused coffee grounds to the pile, as they’re high in acidity and can affect the pH level in the pile. 

These grounds can make the soil too acidic, so it’s best to compost used coffee grounds, as most of the acid ends up in the coffee drink itself. By the time you finish making coffee with your grounds, they have a fairly neutral pH between 6.5 and 6.8. So, adding them to your compost pile won’t hurt anything. 

Of course, you should keep an eye on the pH level to ensure it isn’t out of whack but used coffee grounds shouldn’t cause issues. Keep in mind that decomposing coffee grounds can produce an unpleasant odor, so make sure you mix them into your compost pile (hopefully a sealed bin or an outdoor bin at least 10 feet away from the house) with other ingredients. 

What Can I Do With Used Coffee Filters?

If you don’t have a compost pile, you can always repurpose the filters in a different way. Here are a few options for reusing your used coffee filters:

  • Brew more coffee: Surprisingly enough, you can use most coffee filters about four or five times before they stop working effectively. So, feel free to dump out the old grounds and reuse the filter. 
  • Arts and crafts: Used coffee filters have a beautiful stained brownish color, making them perfect for various art projects. Kids and adults alike may enjoy making multiple crafts, such as flowers, garlands, collaged art, etc. 
  • Deodorize shoes: Pour a few tablespoons of baking soda into a coffee filter and use string or a rubber band to tie it into a bundle. Pop it into the toe of stinky shoes for deodorizing effects. 
  • Germinate plant seeds: Place a few seeds inside a clean, used coffee filter. Moisten the filter with a few spritzes of water, then put the entire thing in a plastic bag or container until the seeds germinate. Transfer the seedlings to a pot of soil when the roots start to show. 
  • Strain grease: Throwing away large amounts of kitchen grease seems wasteful. So, reuse your kitchen grease by straining it through a coffee filter to remove impurities. Make sure the grease is cooled before you pour it through the filter. 
  • Protect fine dishes: Fine china and other delicate dishes tend to wear and chip when stacked. Protect the dishes by setting a clean coffee filter between each plate or dish in the stack. You could also use the filters to protect other items in storage, such as delicate Christmas ornaments. 
  • Sewing projects: If your sewing project requires paper backing, use clean coffee filters for extra support. They’ll tear away easily, yet offer the minimal support necessary while sewing. Before you use the filter as backing, ensure it is well-rinsed and dried, as it could otherwise stain the fabric.