Used coffee grinds are already pH neutral and are a great addition to your compost pile, or your garden! Unused coffee grounds are VERY acidic, I dump old, abandoned coffees (roommates who move away) directly on my blueberry plants! Try the Starbucks near you, they typically give it out in plastic bags. In Hamden you can get ’em from Legal Grounds. In New Haven you can get your grounds at Blue State Coffee. Have fun “harvesting” used coffee grounds!