If you go through ground coffee like me, you’ll be producing a lot of spent coffee grounds and possibly filters too.
With people like you wanting to reduce the amount of landfill waste you produce, a key question you’ll have is what to do with all your coffee waste.
Being a natural product, you’d hope that you can safely compost spent coffee. This is true, you can indeed compost coffee grounds. But there a few things to look out for which we’ll go into below.
Is it possible to compost coffee filters too? In principle, yes paper coffee filters are compostable. The main issue here is whether they are bleached or not.
Let’s get into the details so you can be fully informed on where you stand with composting coffee grounds and filters.
Can you compost coffee grounds?
Coffee grounds are 100% plant based coming from either the Arabica or Robusta coffee plant. This means that they will breakdown into its constituent organic parts over time no problem.
Yes, you can compost coffee grounds.
Even though roasted coffee beans are brown, they are classed a ‘green’ compost waste for their higher nitrogen concentration. Brown compost waste, such as paper coffee filters discussed here and twigs, are carbon rich.
In total, it’s suggested that no more than 20% of the total compost volume should be made up of coffee grounds. A good compost pile needs a fine balance of different types of organic waste and minerals. Too much of one material will cause an unwanted tip in the balance.
You can even get compostable coffee packaging now such as:
On this topic, foil-lined coffee bags are still not recyclable. Have a read of this blog on if you can recycle coffee bags.
Can you add coffee grounds to soil?
You can add coffee grounds to the soil, but from what I’ve read, I’d stay away from adding coffee grounds directly onto the surface of soil as a mulch.
Although it’s quite popular for blogs and other websites to say add coffee grounds to soil, there isn’t much evidence to suggest it helps. In fact, anecdotal evidence suggests applying coffee grounds to the surface of soil doesn’t help plants at all. I’ve also tried it a couple of times over the years but not to much benefit.
The reason that coffee grounds don’t make a good soil mulch material is that it is caffeinated.
Caffeine is a compound that evolved to be used by the likes of coffee plants and tea plants to ‘poison’ the soil. The result of this is to inhibit other plant growth, reduce germination and competition! So, depending on the type of plant, adding coffee grounds to your soil might actually do more harm than good.
Are coffee filters bad for the environment?
When talking about coffee filters here, I’ll be discussing the paper coffee filters. There are other types of filters out there, but paper is the most common type of single use coffee filter.
Coffee filters papers generally come in two camps:
- Unbleached filters
- Bleached filters
Like all paper, coffee filter papers come from a tree, which naturally give the paper a brown colour. Unbleached coffee filters still hold this brown colour. Bleached coffee filters however have been treated so they appear whiter.
Bleached coffee filters have usually been treated with a chemical agent, such as chlorine, to change their colour. Treating with chlorine can cause environmental issues when the filter starts to decompose in nature. You can have a read on whether bleach is bad for the environment here.
A study in 2012 found that chlorine-bleached coffee filters can cause environmental issues in pulp and paper mills, so I think it’s fair to say that this can be a problem in nature too.
There are other types of bleaching however that are more environmentally friendly, such as oxygen bleaching.
So, the difference between bleached and unbleached coffee filters is purely aesthetic. There is no other benefit.
Do filters affect the taste of coffee?
Some people may say they affect the taste of the brewed coffee differently.
Neither bleached nor unbleached coffee filters should impact the flavour of the drink too much if at all. This may depend on the quality of the paper and if you have a professional coffee taster palate or not.
I have used both types of filters in the past and have never noticed a difference. With either type of coffee filter, make sure you rinse the paper before use to try and get rid of the chance off-flavours being filtered through with the coffee. Of course, you want to be tasting the entire quality in your ethical coffee.
As with most products and resources, all coffee filters require a certain amount of manufacturing and will therefore have some form of associated carbon footprint. Composting your coffee and coffee filter papers will help reduce the environmental impact by eventually putting the useful minerals back into the soil.
Bleached or unbleached coffee filters – which are compostable?
Ok, so we know the actual used coffee grounds are compostable but what about the filter papers?
If your coffee filters have been bleached with a chemical agent such as chlorine, they are no longer fully organic. Even though only a tiny amount of chlorine is used in bleached filters, you may not want to include this in your natural compost pile.
Depending on how many filters you go through, depends on how much chlorine could make its way into your compost. As chlorine-bleached coffee filters can have negative environmental issues, I wouldn’t necessarily want to contaminate my decomposing organic mass.
That said, chlorine is a natural element and will break down, meaning you may still be able to compost small amounts of bleached coffee filters papers.
I don’t want to bash chlorine as it does an important job, including making our drinking water safe to drink, and is therefore is safe to use in coffee filter papers but I think it is unnecessary for use in filter papers.
An unbleached coffee filter is slightly less manufactured and doesn’t have any other chemicals added. This means that unbleached coffee filters are better for the environment and compostable.
When buying your coffee filters look out for the common compostable logos and also the TCF (totally chlorine-free) mark.
Even better make sure your filters are sourced from a 100% FSC (Forest Stewardship Council) certified paper source. This let’s you know that the trees grown to provide the paper are grown in a sustainable manner.
Can you put coffee filters in the food waste?
This may depend on your local authority and the rules of whoever is picking up your curbside food waste.
On the whole, yes you can put coffee filters in with your food waste. As we’ve seen, these paper filters are compostable and will breakdown organically.
For me, I use unbleached, compostable coffee filter papers that I put straight into my food waste bin to be collected by the council.
How long do coffee filters take to decompose?
Managing a compost pile can be a precarious undertaking.
Certain conditions need to be created to ensure decomposing is occurring at a decent level. All compost piles require a good balance of green and brown organic waste, as well as moisture, oxygen and heat.
Adding too many coffee grounds and coffee filters could upset the balance and the organisms that are doing the hard work. This will significantly slow down the rate of decomposition.
On the whole you’re looking at 6-8 months for your coffee filter to decompose.
If your coffee filter is added whole to your compost pile, it may take longer to decompose. A good tip is to try and shred the paper up as much as possible to speed up the process and mix it into the pile when added – don’t just plonk it on the top!
Are permanent coffee filters better than paper?
If you’re considering a filter from an sustainable living perspective, then yes permanent coffee filters are better. For taste reasons, this all comes down to personal preference.
Permanent coffee filters, such as stainless steel versions, will filter the coffee differently and potentially not as finely as filter papers would. But because they are fully reusable over time, you’ll be saving a lot of filter paper resource use. Reusing something is always better for the environment than a single use item.
My preferred ‘permanent’ filter is that in a cafetiere. All you need here is the ground coffee which can definitely be composted afterwards. My ground coffee of choice at the minute is the organic Cafedirect Machu Picchu single origin and the sustainable blend at Balance Coffee. The cafetiere filter can then be cleaned and washed out with a bit of soap and water ready for the next use.
A stove top moka also contains a fully reusable permanent filter. Here the water comes to the boil and the pressure forces the water up through the steel filter to the where the ground coffee is and then up through the spout and into the top chamber. Once cooled, clean with soap and water and it’s ready for the next brew.
The coffee filter wrap up
In short, yes both coffee grounds and paper coffee filters are compostable.
Coffee grounds are completely natural and are ultimately like any other plant when it comes to composting.
Paper coffee filters have to be manufactured but they are paper and come from trees. The question of bleached vs unbleached shouldn’t make too much difference to whether it’s compostable or not. Some coffee filters will contain the OK compost logo, or some other accreditation, meaning that no other additive or non-compostable material, such as plastic, has been used to make the filter paper.
Unbleached coffee filters are generally better for the environment and work exactly the same as bleached ones. The only difference here is a case of aesthetics. Why would you want a white filter anyway? This to me is unnecessary.
Brown, unbleached coffee filters are less manufactured, more natural and compostable, which make them a much better choice in my eyes. You can buy your very well priced FSC certified compostable and unbleached filter papers from andkeep.com.
Disclaimer: This post does contain a couple of affiliate links. I only recommend products if I 100% believe in them and have used them myself. Using these links will not change the price in any way but I may earn a commission as a small thank you from the seller.
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