I spoke with the founder of GroCycle, a UK based company that grows Oyster Mushrooms from spent coffee grounds https://grocycle.com/
It turns out that the "sterilization" step that usually needs to happen on a mushroom medium isn't needed on coffee grounds because the espresso brewing process effectively does that,

I'm working on a knockbox design that aims to do something useful with the spent grounds, and one idea I had was the have grounds go directly into a "grow bag" and for the banging of the portafilter to release oyster mushroom seed medium on each layer.

I'm wondering if anyone here has repurposed their coffee grounds to grow things, and also if you have any feedback on my knockbox idea?

I use coffee and espresso grounds in compost and as fill dirt in my yard. Both work well.

I don't know much about how mushrooms are grown in the US, but when I lived in China I was visiting one of my friends' parents home in the countryside. He took me into the "mushroom house", which was basically a long low shack covered in plastic. We wore masks and he reminded me over and over again about not taking it off for a second because of all the bacteria and "black mold". I'm assuming that the right conditions for mushrooms are also the right conditions for a petri dish of other organisms?

I've purchased one of those grow kids at home depot and for the second round used old espresso grounds. It worked really well. Sounds like an interesting idea!

Where can you get oyster mushrooms spores? I'd like to give it a try.

Since you're in Finland, you might be able to order them directly from Grocycle:
https://shop.grocycle.com/products/oyst ... m-spawn-uk

Headala wrote:I use coffee and espresso grounds in compost and as fill dirt in my yard. Both work well.

...

+1, right into the herb garden.

Here you go!

http://inhabitat.com/stylish-coffeemake ... mushrooms/

sweaner wrote:http://inhabitat.com/stylish-coffeemake ... mushrooms/

Oh wow, that is so cool!

decent_espresso wrote:
I'm working on a knockbox design that aims to do something useful with the spent grounds, and one idea I had was the have grounds go directly into a "grow bag" and for the banging of the portafilter to release oyster mushroom seed medium on each layer.

I'm wondering if anyone here has repurposed their coffee grounds to grow things, and also if you have any feedback on my knockbox idea?

Regarding the knock box; sounds like the large bag would only work in a café or where someone had drilled out a hole in their counter; not so much for the home barista? I presume cafes would not bother with growing an herb garden on the side but who knows: might have a real hit with specialty restaurants. I have used spent espresso pucks for revitalizing house plants with some success. My wife has used them for an espresso exfoliating scrub.

Looking at home knockboxes, I haven't seen anything "really missing" about the current designs, except maybe making a short one with a biodegradable bin liner in it. I don't want to make a knockbox just to make one. There has to be a problem to solve. If there's something else you'd like a knockbox to do, or current ones fail you in some way, let me know!