Used coffee grounds is the result of brewing coffee, and are the final product after preparation of coffee. Despite having several highly-desirable chemical components, used coffee grounds are generally regarded as waste, and they are usually thrown away or composted. As of 2019, it was estimated that over 15 million tonnes of spent coffee grounds are generated annually. Due to this quantity of waste and the chemical properties of used coffee grounds, potential uses for used coffee grounds are a hot topic of investigation as of the 2010s.