Knock Box

A knock box is a device used to store spent coffee grounds, called a puck, after a shot of espresso has been pulled. It is generally made out of stainless steel or plastic, and has a sturdy bar known as a "bash bar", against which a portafilter is tapped to release the puck. Because the espresso puck is typically very hot after extraction, knock boxes need to be sturdy. They are subject to repetitive knocking and tapping to dislodge the spent coffee after use, and thus rubber and stainless steel are the most commonly used materials.

The coffee knock box is one of the simplest coffee accessories you can add to your home barista unit and one of the most useful and convenient accessories you can purchase. These coffee bins are used in the disposal of spent coffee grounds from the portafilter after every shot.

Using a Knock Box is more environmentally friendly. Coffee grounds often end up in the garbage because people just don't realize that there is another choice. Not only is this bad for the environment as it results in additional garbage and trash in landfills. The Knock Box allows you to easily store your leftover coffee grounds. At this point, you can empty it into your compost bin, which will turn these coffee grounds into rich fertilizer.

Cleaning your knock box should be done regularly, empty the spent beans into your compost. After emptying, wash with soapy water or you can add the box to your dishwasher. Don't leave your spent coffee build up for a period of time as it will go mouldy.