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Can You Compost Coffee?

If you have been caring for your vegetable crop or flowering garden, you have dealt with this dilemma before. And you are not the only one! Composting coffee can yield great benefits, yet it can be harmful to your plants if you are not careful!

So, can you compost coffee? Yes, used coffee grounds are an ideal addition to your composting pile. Here are a few key things to know about this:

  • Coffee beans, like fresh coffee grounds, are highly acidic and can harm your plants
  • Moist natural coffee filters are compostable
  • Coffee bags and cups are trickier to compost; you should opt for commercial composting. 

If you are a coffee-lover looking at making your lifestyle a little more environmentally-friendly, read on! In this article, find the guidelines you need to dispose of your coffee waste in the best way!

Can You Compost Coffee Beans? 

If you, as the ultimate coffee lover, went a step further and purchased a coffee grinder, you might have also been buying bags of whole coffee beans. Undoubtedly, grinding them at home and preparing your brew can offer you some of the best coffee you can find. However, after you have stocked up on bags of beans, it is reasonable to have some waste. 

If you are looking at reducing the quantity of garbage produced by your household, you should keep in mind that unopened coffee bags will not spoil for over nine months. However, if they have started to go soft and your homebrew no longer tastes the same, you could opt to compost them.

While doing so, there are specific characteristics of whole coffee beans that you should keep into consideration to avoid killing your plants by mistake.

Coffee beans contain high quantities of caffeine

The reason why we all end up drinking gallons of coffee each day? Caffeine! While this stimulant can offer you that energy boost you needed to work a little harder on an important project, it might not have as beneficial effects on your flower plants. 

Indeed, a coffee cup brewed from fresh beans boasts an average of 95mg of caffeine. However, once you brew the beans or ground the coffee, the caffeine level remaining is about 40mg. Yes, there is still a significant amount of caffeine remaining, yet this is almost half of the one contained in fresh coffee. 

As a stimulant, caffeine can aid the growth of your plants and make an excellent fertilizer for your crop. However, high quantities of caffeine, as well as nitrogen, can be incredibly harmful to plants that do not thrive well in acidic soils or are more sensitive to caffeine.

Coffee beans take longer to compost

Similarly to other dry materials and substances, coffee beans, as well as unused coffee grounds, can take much longer to compost. Moreover, they can make your whole composting pile much drier than necessary, which slows down the process. A quick way to determine whether the coffee grounds have turned your bin into a too-dry garbage pile is to check whether decomposition has started to happen.

Moisture and water are indeed essential elements that make sure that the composting process proceeds undisturbed. For this, many gardeners opt to pour the beans and dry grounds directly into the soil. However, as we have seen before, your plants can suffer from too acidic or nitrogen-rich soil.

Can You Compost Coffee Grounds?

Coffee grounds, thanks to the high quantities of nitrogen in them, are one of the “green materials” to add to the composting pile. Oppositely, “brown materials” are those substances that are rich in carbon. Since a well-balanced composting bin boasts similar quantities of the two, coffee grounds make the perfect addition to the pile when it does not add up to more than 20% of its total mass.

However, you should always opt to add used or spent coffee grounds instead of fresh ones. The main reason for doing so is the one we have explored above. However, a second important factor to consider is that your bin needs enough moisture to proceed with the composting process. 

Cultivators and gardeners have also been adding coffee grounds directly into the soil surrounding vegetables and flowering plants. This option is excellent if you are looking for a natural, ready-to-use addition. Among the many functions you can enjoy, coffee grounds can:

  • Be excellent fertilizers for acid-loving plants
  • Work as natural mulch
  • Be natural pesticides that look after your plants’ health

Instead of adding the used coffee grounds into your composting mix, another excellent way to dispose of them is to add them directly into the soil. However, if you opted for this alternative, there are some factors every gardener should consider to guarantee the health of the plants.

Coffee is rich in nitrogen

Nitrogen is an essential chemical element that plays a crucial part in the growth and wellbeing of plants. Indeed, you can find this substance in various quantities in most commercial fertilizers. By checking the label of the fertilizer you have selected, you can even find out how much nitrogen you are directing into the soil!

However, if you like to feed your plant only natural, home-made supplements, you could use coffee grounds instead! Nitrogen makes up for 2% of the total mass of coffee grounds, making them one of the most nitrogen-rich natural substances you can find in your pantry.

You can find nitrogen naturally in the chlorophyll molecules, the ones responsible for the green color of our plants. If the soil is rich in nitrogen, you will notice your plant growing a strong, healthy, and verdant foliage. The other two essential elements that benefit the development of your greens are potassium and phosphorus. 

However, each of these chemicals has different functions. While nitrogen aids the development of foliage, it does not improve the quality of flowers and fruits. Opt to add this substance to plants that are not fruit-bearing to see the best results. 

Moreover, coffee grounds are low in phosphorus, calcium, and potassium. If added to flowering and fruit-bearing plants in large quantities, it might result in smaller, less healthy, and diseased fruits. 

These considerations are just as valid if you prefer to compost your coffee grounds traditionally. Indeed, by adding more than 20% of coffee grounds into the composting pile that you will use as fertilizer, you might achieve similar results.

Coffee can alter the pH of the soil

After you have brewed the coffee, the pH of the coffee grounds remains stable at a value of around 6.7 on average. Oppositely, the pH of your soil can be anything between 3.5 and 10. Even though the coffee itself is only barely acidic, it can alter the pH of your soil by lowering or increasing its acidic level.

In turn, this factor could help some of the acid-loving plants in your garden thrive. Blueberries, azaleas, onions, and broccoli, among many others, prefer slightly acidic soil. If you are cultivating any of these plants, adding coffee grounds into the land can be a great solution to see your crop grow healthy!

In any case, you should incorporate the coffee into the soil instead of just creating a layer atop the surface. By doing so, you are making sure that the roots of your plants can effectively reach the nutrients provided by the coffee. Instead, if you cover the surface of the soil only, this might create a layer that traps the moisture in, preventing the circulation of new water and supplements. 

Make sure it is all-natural!

If you are looking at giving a second life to the used coffee grounds by adding them to your composting pile or in your crop’s soil, you should first ensure that they are entirely natural. Indeed, many manufacturers and roasters add flavorings to their products for marketing and quality means. 

If you need large quantities of coffee grounds to feed a large crop or garden, avoid collecting them from a coffee shop unless you have checked that they only use natural products. Even better, try only to use the grounds you have at home after brewing your morning coffee!

In this way, you will avoid any detrimental chemicals and dangerous artificial flavoring from entering the ground of your crop. Indeed, the roots of your plants will collect and absorb nutrients from the surrounding compost and soils. In turn, these will end up in the fruits of the plants that you will then bring to your dinner table!

Can You Compost Coffee Filters? 

Coffee filters contain both the nitrogen-rich material (the coffee) and the carbon-rich substance (the paper), which balances out the first one. This factor makes them one of the most significant additions to better the environment of your composting bin. However, there are some essential differences between filters and coffee grounds to remember.

Are your coffee filters natural?

If the filters you usually use are entirely natural and made of paper, you can add them to your composting bin without thinking about it twice! The external envelope of your used grounds has a similar effect as newspapers and cartons in the composting process.

Brown materials, being made of carbohydrates, provide a steady food source for some of the organisms that will help break down the pile. Of course, a balance with green materials is essential. However, when adding brown elements to the stack, you should check whether these contain harmful or toxic ingredients.

Indeed, the ink from the newspaper sheets and the glue from your card boxes can quickly spoil the quality of your composting pile. Even worse, such substances can end up in the vegetables and fruits you are growing! 

Coffee filters are no different in this case! If they contain any other substance that is not plain paper, they might end up adding toxins to your composting pile. Before throwing such filters into the bin, make sure they do not include:

  • Plastic coatings
  • Metal fragments
  • Inks
  • Oil-based inks
  • Bleach

These chemicals are widely used in the productions of filters, making them not biodegradable or compostable. You can find out all the substances in the filters by reading the container. If you are using such filters, you should consider swapping them for a more environmentally-friendly brand that only uses paper-based filters.

Instead, if you have already opted for such greener filters, you can relax! Paper is biodegradable and can make a great addition to your filling bin.

How long do coffee filters take to decompose?

The second factor to consider while placing your coffee filters in the bin is that they can take longer than other materials to break down. If you are looking at enjoying the newly-made fertilizer in a few weeks, you should know that coffee filters can take anything between six and eight months to decompose finally. 

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To speed up the process, you should break, tear, or cut the coffee filter into the stripes or pieces. This process allows the paper to mix up with other materials that boast higher moisture levels. Other tips to get your coffee filters to break down quicker are:

  • Avoid leaving them on top of the pile where they would dry out quicker
  • Make sure thy boast some level of moisture before adding them to the bin
  • Shred them so the microbes can work their way through their surfaces much faster

Can You Compost Coffee Cups/Bags?

Today, no coffee shop does not offer a takeaway option. In many cases, these cups proudly boast the “compostable” or “recyclable” sign that makes their buyer feel good about themselves. However, are they genuinely, wholly compostable?

Any coffee lover ends up with an unwanted collection of cups and bags at the end of the month. For environmentally-conscious people, this can quickly become a pressing matter! Below you can find out how to dispose of your cups and bags safely and without affecting the planet!

How you compost your cup does matter!

If a coffee cup or lid boasts the “compostable” sign, simply it means that it is compostable. However, the way you are composting matters! Indeed, to properly compost a coffee cup to make sure that the organisms do their job and dissolve it into usable fertilizer, it is not enough to throw it in a generic bin!

Coffee cups present an outer layer made of carton, while plastic lines the inner side of it. Due to the different materials used for their production, coffee cups are only recyclable or compostable in controlled environments. Even worse, many users tend to be confused regarding where to place them for the best results!

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While your intention to compost them is very noble, you should remember that home composting varies from a commercial composting facility in many different ways. Since usually, the plastic layer is inseparable from the carbon side, avoid adding them to your compost pile. By doing so, you could be contaminating the rest of your brown and green materials. Such a practice could result in eco-littering.

Can I throw the whole coffee bag in the composting pile?

Coffee-lovers that prefer to brew their morning coffee at home also have to face another dilemma. Where do you place the coffee bags to compost them safely? These can quickly add up in your pantry and contribute to the amount of garbage that a household produces. However, such containers are incredibly tricky to compost!

Coffee bags boast a one-way air valve that allows the gas produced by the coffee ground or beans to escape the package. In the meanwhile, this device makes sure that no external air enters the container, keeping the coffee fresh throughout the months. To compost them, it takes quite a bit of effort on your part!

First off, you need to check the composting instructions on the bag, as well as what materials compose the package. Even the bags labeled as “compostable” might not be entirely suitable for home processing. Follow the steps below to see the best results!

  1. Remove the valve. This part of the bag is never compostable, so you should remove it.
  2. Remove the tin tie. Metal cannot decompose in your composting pile
  3. Check whether the bag boasts an internal plastic layer. Remove it if necessary.
  4. Place the external paper-based layer in the composting pile. If there is ink or prints on the paper, avoid adding them to your home composting as they can release toxins.

Final Thoughts 

Composting a portion of the produced waste at home can be an excellent solution for anybody who is trying to live a more environmentally-friendly lifestyle. Coffee, and all the materials related to it, tend to add up to large quantities in any household. That is why it is crucial to understand how to compost it properly. Used coffee grounds are the perfect addition to your pile and can even be an excellent fertilizer for your crop. 

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However, coffee cups and bags need a little more effort to compost them adequately without contaminating the surrounding environment. Coffee beans and fresh grounds boast large quantities of caffeine and should be added to the pile with caution and should not make up anything more than 20% of the total mass.