Ways to reduce coffee pollution: Composting

The time to reduce coffee pollution is not confined to its production stage. After brewing a cup of joe, the next likely course of action would be to throw the coffee grounds (CG) away. However, these CG, being organic, releases methane upon decomposition, which has a warming effect 84 times higher than that of carbon dioxide (Vaidyanathan, 2015). So what can we do to prevent such pollution?

A quick Google search would most probably direct us to compost CG as they contain potassium and nitrogen that are essential to plant growth. CG can also aerate soils and improve soil drainage, which can improve the roots ability to uptake water and nutrients. 

Image 1: Some benefits of using CG as fertilizer. Source: The Spruce, 2021

A quick guide to starting composting can be found here. The article in the link basically summarises three different ways to use CG as fertilizers. 

Adding CG:

1. directly to the soil

2. into a compost pile

3. into a compost system

Going with the compost pile method would be the safest and most economical route. However, if one decides to add CG directly to the soil, a note of caution would be to avoid adding excessive grounds. Excessive grounds can cake up and prevent water from infiltrating the soil, thereby dehydrating the plants instead of helping them to grow. One may also decide on a compost system, which generally involves purchasing decomposers, which personally can be a little expensive or repulsive.

While composting helps in recycling CG, some have advised against using CG as fertilizers as they can be acidic, and they contain caffeine, which may be detrimental to plant growth (Besemer, 2021). However, spent CG are almost pH neutral and according to trees.com, the caffeine content is less harmful to mature plants than seedlings. This suggests that with proper knowledge on the dos and don'ts, CG as fertilizers can be largely beneficial to our plants at home, and we can save money on fertilizers while reducing pollution.

Image 2: Plants with (left) and without (right) the use of CG fertilizer. Source: Sacha, 2018

Overall, before we start composting, it is best to read up on the good practices and plan out our composting methods. With the proper techniques and enough support for coffee composting, perhaps pollution levels can dip, even just by a little.