[6] It is not recommended to burn dried used coffee grounds, as they give off hazardous nitrogen oxides when burnt.

They are said to be especially appreciated by worms and acid-loving plants, such as blueberries,[12] although due to acids being leached from the grounds while in use, they typically have a neutral pH,[13] and red wiggler growth and survival has been experimentally tested and found to be reduced in treatments using used coffee grounds as the primary feedstock for the worms.

[22] Used coffee grounds have other homemade uses in wood staining, air fresheners, and body soap scrubs.

[25] It has been proposed to use spent coffee grounds to feed ruminants, pigs, chickens and rabbits, but the high lignin content makes this an undesirable use.

[18] Bioethanol may also be produced from the sugar content of spent coffee grounds, after it is defatted as a pre-treatment, it is typically hydrolysed by dilute acid.

[30] It has been suggested to recover caffeine from used coffee grounds for commercial applications in agrifood, cosmetic, nutraceutic or pharmaceutic industries.

[31] In 2021, Gloucestershire-based football club Forest Green Rovers trialed a kit made from 35% used coffee grounds combined with recycled plastic.