It’s the first time I see someone use coffee for this. If it really works it’s gonna be very convenient use of the waste. I only don’t like the plastic container. It feels really out of place.

Coffee beans (roasted) really have the ability to absorb moisture - they are hygroscopic, but in the case with already brewed, I don’t think that this will work. They first have to be dried and only then they can absorb more moisture.

Very informative post!