We know that the coffee used is excellent for the compost pile. But there is not much scientific literature on the impact of using them in composting, or even if they are biodegradable. Generally, when there is little data available on a topic, it means that no problems have been reported.
However, most white coffee filters used today are bleached and, according to a Colorado State University study, “…coffee filters and paper towels may have been treated with synthetic chemicals and bleach. Those trying to maintain an organic garden will need to consider these possibilities before throwing items into the pile. “
Pros and cons of putting filters in the compost
Yet other sources believe that bleach has pretty much dissipated by the time it gets to your compost and will not pose a threat to your soil or you. If you are concerned about bleach, unbleached filters are available. Of course, if you were using a reusable filter, this conversation would be academic.
On the positive side, coffee filters biodegrade very quickly, if they are covered and in a moist compost pile, and the worms seem to like them. If they are allowed to dry, they take much longer to decompose. Filters would be considered a “brown” or dry ingredient, which can be hard to find in the lush summer peak and essential to keeping your compost pile balanced.
Some concerns about composting used coffee filters and coffee grounds
Coffee is generally considered a good ingredient for the compost pile. Although it is dark in color, it is considered a “green element” because it is a rich source of nitrogen.
However, some people are concerned that composting coffee will change the pH of the pile. Coffee is acidic, but acid is soluble in water, so most of the acid is in the liquid we drink and little remains in the soils used. By the time the soils get to your compost pile, they have a fairly neutral pH that is somewhere between 6.5 and 6.8 and perfect for adding to your compost.
A word of caution about using straight coffee grounds as mulch in the garden; decomposing soils can produce a very unpleasant smell. If you have ever kept them in a kitchen countertop compost bin for several days, you will be familiar with the smell.
They also tend to harden and cake, making it difficult for water to pass through and unpleasant to see. It’s better to throw them in the compost pile where they will be mixed with other ingredients than to try to use them directly. Don’t throw them in the garbage or waste them.
What about coffee grounds?
Don’t throw away your coffee filters containing coffee grounds! We will see together that this waste, apparently like any other, hides real virtues that will only be beneficial to your plantations.
Indeed, coffee grounds are full of active ingredients and are rich in nitrogen, phosphorus and potassium (elements that are essential for the good growth of your plants).
It would be a shame to do without this treasure, which I’m sure is in your kitchen! To do this, nothing could be simpler: after brewing your coffee, simply collect the filter with the coffee grounds and store it in an unsealed container to prevent the coffee grounds from becoming moldy. The grounds will dry and will not lose any of their properties.
What are these famous virtues? How to use coffee grounds in the garden?
Coffee grounds can be used as an organic fertilizer (be careful not to use too much either!) either by depositing it in a thin layer at the foot of your plants, or by incorporating it in your soil during hoeing or scratching. The rain will distill the nutrients directly to the roots.
Coffee grounds and their filter can also be deposited in the compost bin located in the Pierre Valette shared gardens. They will help the degradation process of the waste already present! It is highly recommended to regularly add coffee grounds to the compost in order to enrich the future soil with nutrients.
You can also use coffee grounds as a pest repellent. Snails, slugs, aphids and other carrot flies do not like coffee because of its texture and strong smell. If you place coffee grounds around the plants you wish to protect, the pests should be repelled and therefore, you will preserve your crops without having used any chemical product!
This alternative to chemical insecticides is in short a very good solution for the garden, so why not try it?
What can be put inside the compost?
Once the compost is installed at the bottom of the garden, it must be filled. But what can you put inside? Among the different types of waste, some can be put in the composter and others not.
For a good compost, always remember to balance and vary the waste. For example, compost requires wet waste (green material), dry waste (brown material) and water. You can put fruit and vegetable peelings, crushed eggshells, tea bags, coffee grounds and filters, but also dead leaves!
What should not be put in the compost?
Be careful, some wastes don’t belong in the composter. It can even be harmful for plants. So avoid putting food oil and grease, but also charcoal ash (after a barbecue), vacuum cleaner dust, clay cat litter, soil and sand, or even rags and textiles.