It is not particularly acidic, most of the acidity in coffee grounds ends up in your coffee. Even if it were more acidic, changing the soil ph would require so

It is not particularly acidic, most of the acidity in coffee grounds ends up in your coffee. Even if it were more acidic, changing the soil ph would require so much that you probably wouldn't worry about it unless you ran a cafe and used all the waste on your garden. I'm using my experience of trying to maintain more acidic soil around my blueberry bushes, and all the coffee bean waste from my kitchen wouldn't make a difference even if it was very acidic (which it isn't).