RamMasterFlash said: All that coffee causes high acidity though, and one thing you can do that is fire related is to add in wood ash.
Despite the repeated hype that is not really an issue.
Coffee beans are acidic. Brewed coffee is acidic. The spent/used coffee grounds are only mildly acidic; the acidity largely winds up in your cup. Spent coffee ground are in the PH range that most plants do well in. That's before we get around to mixing them into soil directly or into a compost heap where their effect is going to be even smaller.