Can You Compost Coffee Grounds: Here’s How & Why To Do It!

Last updated on October 23rd, 2023 at 08:59 pm

Coffee is probably one of the most popular hot beverages in the world and the good thing is that coffee grounds are an all-natural, biodegradable substance.

Does that mean you can compost coffee grounds? If so, can you also compost coffee grounds in filters or coffee pods?

Can You Compost Coffee Grounds: Here's How & Why To Do It!

Whether and if so, in which forms you can compost coffee grounds you will find out in this article.

Kann man Kaffeesatz kompostieren

As a purely natural, biodegradable substance, coffee grounds can be composted without hesitation. It can be composted both in pure form, e.g. from a portafilter or fully automatic machine, and in the filter. For composting coffee grounds in the filter, however, only unbleached filters should be used, which is also usually the case with coffee pods. Since coffee capsules are made of aluminum or plastic, they must not be composted under any circumstances.

Can coffee grounds be composted?


Since coffee grounds are a completely natural, 100% biodegradable substance, they can be composted without any problems.

More specifically, coffee grounds are the waste product left over from the coffee-making process after coffee powder has been brewed with hot water.

Since coffee grounds are ground coffee beans, which in turn are the seeds of the coffee plant, coffee grounds are therefore nothing more than an organic material that can be fully composted.

One could therefore compare coffee powder with, for example, ground sunflower seeds: both are fruits or seeds of the respective mother plant that can be composted and that decompose completely.

Coffee typeExamplesSuitable for composting?
Coffee grounds in filtere.g. brewed from a classic filter machine or with a filter containerYes, but only unbleached coffee filters* should be composted – but then possible without problems
Coffee padse.g. coffee pods* from a classic Senseo coffee machineYes, without restriction since the pads are normally also made of unbleached filter paper
Coffee capsulese.g. from a capsule machine like NespressoNo. Coffee capsules* are partly made of aluminum and plastic. Depending on the manufacturer, they therefore belong in the residual waste or the yellow bag.
Pure coffee grounds from a portafilter or fully automatic coffee machinee.g. from a fully automatic coffee machine or a portafilter machineYes, without restriction

Can coffee grounds in the filter be composted?


Coffee grounds in the filter can be composted without problems as long as unbleached filter paper is used.

Unbleached filter paper can usually be recognized by the fact that it is somewhat brownish or natural brown (such as this paper from Melitta), whereas bleached filter paper is completely white (such as this variant also from Melitta).

Coffee grounds in bleached filter paper should not be composted, as various chemical substances, especially chlorine, are used in the bleaching process of the paper.

Even if the residual amounts of the chemicals in the paper are small, you should avoid using them in your own compost.

So if you want to compost coffee grounds in your filter, just buy unbleached filters, which by the way cost the same as bleached but are still much more environmentally friendly 🙂

Can coffee pods be composted?


As long as coffee pods only contain coffee powder, they can usually be composted without any problems as the filter paper of coffee pods is made of biodegradable cellulose.

However, you should make sure that you do not compost pads from other products, such as lattes* or hot chocolate*. This is because such pads sometimes contain plastic particles or sugar inside – both substances that have no place in the compost.

Did you know that coffee grounds can also be used as fertilizer for certain plants? If you want to know more about this topic then check out the article I linked here on the right.

Can coffee capsules be composted?


Coffee capsules* can in no way be composted because they are made of aluminum or plastic, which is why they are not biodegradable and would not rot in the compost.

Although coffee capsules lock in the coffee aroma very well, not only the production of the capsules but also the recycling is very resource-intensive and therefore not very environmentally friendly.

Coffee capsules are available from various manufacturers, some of which are made of aluminum or plastic. Both materials have nothing to do with the compost and therefore coffee capsules should not be composted under any circumstances.

Can coffee grounds from a portafilter machine be composted?


Pure coffee grounds, for example from a portafilter or a fully automatic coffee machine, can be composted without any problems.

The great thing about these forms of coffee production is that no other waste product is produced besides the coffee grounds.

So the coffee grounds from a portafilter machine can go straight to the compost without any detours or concerns.

No matter in which form you compost coffee grounds, you should make sure that the coffee grounds are somewhat dried.

On the one hand, because the risk of mold is greater from moist coffee and on the other hand, because rain worms and compost worms like loose, dry coffee grounds much better.

It’s best to let the coffee grounds dry in a shallow dish or extra container, for example, before adding them to the compost.

How much coffee grounds can you compost?


Depending on whether you drink a lot of coffee or only an occasional cup, different amounts of coffee grounds will naturally accumulate.

Since coffee grounds are acidic due to the tannic acid they contain, you may be wondering how much coffee grounds can be composted without overburdening the compost?

Overall, it’s safe to say that you can dispose of coffee grounds in all household quantities in your compost without worry!

More specifically, the total amount of coffee grounds in the compost can be about 10% of the total compost volume.

Let’s say your composter has a volume of 600 liters and you drink an average of 2 cups of coffee per day.

Per cup, you use about 7 grams of coffee powder as standard. This results in about 5 kg of coffee grounds per year (7 grams * 2 cups * 356 days) or 10 kg for a 2-person household.

Thus, the 10% of compost (which corresponds to about 60 liters or 60 kg) is far from being reached if two people in the household drink two cups of coffee every day.

Advantages when composting coffee grounds


Composting coffee grounds can offer a whole host of benefits.

In addition to being a responsible use of natural resources and recycling materials, coffee grounds have positive effects on compost due to their structure and constituents:

Benefits of the texture of coffee grounds

Due to its ground, powdery nature, coffee grounds add looseness to the compost pile.

The small voids are ideal for air circulation and for small animals and bacteria to thrive.

Most importantly, the loose coffee grounds attract rainworms and compost worms. They feel very comfortable in the material and deposit their worm cocoons there.

Ingredients of coffee grounds and their effect

Coffee grounds consist of important ingredients that stimulate plant growth and provide stability and beautiful maturity or flowering.

The three main active ingredients contained in coffee grounds – nitrogen, potassium and phosphorus – are also contained in almost all commercial vegetable or garden fertilizers (such as Compo or Dehner).

IngredientEffect
NitrogenStimulates plant growth
PotassiumPromotes cell growth and stability of the cells, which give the plant steadiness
PhosphorusHelps throughout the growth and ripening especially fruit, vegetables and flowering plants.
Tannic acidHas a slightly acidic effect (pH <7), which can serve as an antithesis to lime (alkaline, i.e. with pH >7)
AntioxidantsServe as cell protection and can thus prevent damage (e.g. due to solar radiation or pollutants)

Author

  • James Jones

    Meet James Jones, a passionate gardening writer whose words bloom with the wisdom of an experienced horticulturist. With a deep-rooted love for all things green, James has dedicated his life to sharing the art and science of gardening with the world. James's words have found their way into countless publications, and his gardening insights have inspired a new generation of green thumbs. His commitment to sustainability and environmental stewardship shines through in every article he crafts.

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