Hiya,

I'd like to share a method I use to remove coffee grinds from the basket of my espresso machine. Instead of whacking the portafilter on a knock box, which would occupy too much space in my small kitchen, I use a wooden mallet to whack the coffee grinds into a compost bin, located under the sink. The mallet doubles as a kitchen top protector when tamping the grinds. Works like a charm and takes very little space.

I've documented the build of my current mallet over at instructables:
http://www.instructables.com/id/Wooden-Mallet-AKA-The-Coffee-Puck-Smasher/

This may be not everybody's 'cup of tea' , but it works for me. The attached image shows my new mallet alongside my old, now-replaced, smashed-to-pieces mallet.

Good job. That's thinking outside the (knock)box.

You can also just lay a wooden spoon across the top of your trash can and smack the portafilter against it. That is what I use to do in the office.

I see that you are from Holland.

I don't know why you bothered. Couldn't you just take one of these wooden shoes you have there lying around and knock your puck out?

How about a rounded wooden stick across your compost bin?