Tackling youth unemployment by growing mushrooms from coffee waste | Hacker News Reader

Tackling youth unemployment by growing mushrooms from coffee waste

independent.co.uk

63 pointspmoriarty40 comments

> Urban Mushrooms has already stopped six tonnes of coffee grounds from going to landfill.

As a late 80s kid I remember being told that nutrients sent to Landfill were there forever, essentially lost because landfills are sealed off from the wider ecosystem. I mean some gases get out and I guess some stuff gets eaten by birds, but mostly it's good organic matter locked away forever. So anything which saves organic gunk is good with me.

> Urban Mushrooms currently employs two staff and several apprentices

The impact on youth unemployment, though, seems kind of minimal.

> Urban Mushrooms has already stopped six tonnes of coffee grounds from going to landfill.

What happens to the coffee grounds after the mushrooms are done growing? Not trying to be a smartass. Genuinely curious given this is a core claim.

Regarding landfill, I've wondered if these site will be come super valuable in 100 years type thing. There must be huge mineral wealth someone will mine from these one day. Kinda like us mining old mines tailings now our extraction methods are better.

Yes I've wondered the same. 1970s solid-state electronics full of gold, metals lying around everywhere, rare earth metals in old cellphones, recylcable glass and plastics... Wanna co-found a startup that buys old landfills?

I'm interested! I've done small-scale precious metal reclamation, also silver castings and home forgings. Basically that makes me an expert ;)

As someone with no knowledge of this, how do you do small-scale precious metal reclamation and how did you get into home smithing?

Here is a link to a popular scientist YouTuber who has done significant work in this area

https://www.youtube.com/playlist?list=PLKhDkilF5o69PqPy-oMCC...

Well worth the watch

I built a forge a few years ago with a bucket, plaster of paris, some quartz sand, some iron pipe and a blow dryer. Then I started hammering on steel when it turned red.

Metal reclamation is just chemistry so youtube and grainger are all you really need.

It is already being done. Dealing with old piles of trash is somewhat dangerous (all sorts of volatile gasses build up there) but once you get around this you can burn the thrash (releasing quite a bit of energy) and go through the ashes later. The ash can be used for various purposes, such as construction, but needs to be sorted by grain size first. While going through the ashes you do indeed encounter precious metals. I recently read about a company that performs this sorting as a service. They are not paid for the work directly, but get to keep the gold (and possibly other metals?) they find. Apparently you can expect to find a gram or two of gold in a tonne of ash.

That doesn't sound like much? That's less than 100USD per tonne (approx $40/g current gold price)

Is there much other valuable stuff in the ash to make the venture worthwhile?

I dug up the original article for some fact checking, and it seems my previous post has a few mistakes in it. There are "grams" of silver and gold (each or together? The article does not specify.) and "kilograms" of copper in a tonne of ashes. Other metals are also extracted, but their amount or value is not specified.

It further turns out that there is a monetary payment for the service, but it is low because of the valuable metals. The article also tells that the machine can sort around 100000 tonnes of ashes annually.

According to this article, a good open-pit gold mine has deposits of about two grams per tonne.

http://www.mining.com/web/making-the-grade-understanding-exp...

Spent mushroom substrate is really good in compost (particularly vermicompost). I worked on a small scale gourmet mushroom farm earlier this year, it's easy enough to sell the spent medium to gardening businesses when you're done growing mushrooms.

I think all coffee grounds make decent fertiliser too, as well as decent compost, even without mushroom.

coffee grounds alter the pH of whatever you use them in so you can't just blindly use it as fertilizer. Just an FYI before people start throwing their coffee grounds everywhere. It's worth researching whatever your growing to see what pH it prefers and then treat accordingly.

They also just get moldy in "sterile-ish" environments like pots since there's nothing there to break them down. Works ok in the yard though.

Gourmet mushroom farm? Can you tell more?

It was at What The Fungus - you can check them out on youtube

thanks, great name and sorry for the late reply!

For youth unemployment, I would propose granting kids some credits toward college/uni for doing summer farm work. It’s dirty and rough, but the more people are connected to their food the better.

Having worked with some small farms that sell boutique $VEGETABLE at absurd prices I don't think those are the kinds of businesses I want to subsidize with cheap labor (i.e. higher quality than they could otherwise get at that price point as a result of the college credits).

Construction is probably a better choice because there's far more diversity to what the field entails and it provides real world context for many more degree programs than farming does.

Why not offer the kids a choice? Farming offers many lessons beside the agricultural part like economics, managing, husbandry..

> . I mean some gases get out and I guess some stuff gets eaten by birds, but mostly it's good organic matter locked away forever.

...essentially sequestered carbon.

I generally support recycling and climate action, but I actually wonder if the net benefit of throwing organic matter in landfills could be carbon negative if the gases are controlled. For organic matter, putting it in a landfill could potentially be a net positive versus recycling it or composting it (which also releases gases).

The landfills often tap the fill for methane generated by the contents. I happened to run into a guy the other day who worked at the power generation plant for one of these. The theory is that burning the methane to produce electric, and breaking it down to CO2 is generally preferable than the slow leak of it into the atmosphere where methane has a stronger greenhouse gas effect than CO2.

Edit: stronger not "strong"

In Vienna, Austria there's http://www.hutundstiel.at (german only for some reason). They also grow oyster mushrooms on coffee waste and even pick up the waste by bike.

Recently there are even sausages made of oyster mushrooms (http://www.hermann-fleischlos.at also german). What's interesting about them is that they taste incredible (vegetarian soy based sausages I tried are really terrible).

Anyway, it's really good to see some innovation going on with mushrooms!

We grow oyster mushrooms at home using our used coffee grounds. I think we get about two portions for meals each 5 weeks. We use a grow kit from https://www.rotterzwam.nl but I think you can easily do this at home. It's really fun and easy and you get some tasty mushrooms as a reward :)

In Switzerland, Nespresso capsules are recycled a fair lot. You can find nearly anywhere nespresso capsules bins. Even more, when you buy capsules online, they give you a bag for you to throw your used capsules in. Once full, you simply drop it in your mailbox and the mailman takes it away.

They are then recycled: the aluminium is smelted, and the coffee grounds digested into methane which is then reinjected into the gas network

http://www.bttrventures.com/ has been doing this since 2009

How "easy" is it to grow poisonous mushrooms in one's coffee waste? What sort of care do enthusiasts have to take?

Very simplified:

1) Make sure that the growth medium is as close you can get to being sterile

2) Make sure that only spores from the desired mushroom is "planted" in the medium

If done properly, the desired mushroom will outcompete the others, deploy its own defence mechanisms to keep others out.

This is my main hobby outside my software gig. You're extremely unlikely to grow poisonous mushrooms, the main problem you have is with unwanted moulds or bacteria. As kartoffelmos says below, you need to sterilise the coffee (creates a blank slate) or pasteurise it (keeps beneficial bacteria in the coffee). A lot of the time, if you get super fresh coffee, it's effectively already been pasteurised and you just need to introduce mushroom spawn to it.

If you like experimenting and growing your own food, it can be a really interesting hobby

Do you have some more information or links for anyone that would like to get started?

Beginner info / what type of environment to use or is ideal / tips for dealing with mold, bacteria / common beginner mistakes / etc.

Not OP but I have a bunch of books from Paul Stamets who is pretty much the mushroom king. I think one of them is very much a “how-to”.

I am also interested.

Not sure where you're based, but as a first step, I'd probably recommend buying a oyster mushroom grow kit locally or online. All you need to do is mist it daily and you'll get oyster mushrooms in about a week. It will give you an idea of what success looks like.

If you like that, then the next level of difficulty is creating your own fruiting kits using mushroom spawn. I'm in Australia, but you can buy it from somewhere like here if you're in the US: http://out-grow.com/live-mushroom-spawn-c-12/. You basically mix the spawn with treated straw or sawdust and put it in containers, the spawn will colonise and shortly after you'll get mushrooms. Most sites will recommend you sterilise or pasteurise the straw/sawdust (they call this the substrate), but the easiest way to grow without pasteurising/sterilising is using paper, see here as an example: http://re-thinkgreen.com/2016/02/24/mushroom-kit/

Stamets is regarded as the guru, but I think "The Essential Guide to Cultivating Mushrooms" (https://www.amazon.com/Essential-Guide-Cultivating-Mushrooms...) is a better starting point for the beginner. You don't need to be as much of a clean freak as he makes out, there are plenty of low-tech methods.

I'm in the process of writing a short guide on growing shiitake at home, it's harder than oyster mushrooms but once you get the basics it's pretty easy too. It's pretty crazy the amount of mushrooms you can grow with basically no space, you can see my son here with some we harvested recently: http://www.mushroom.guide/

If you're in a bigger city, there should also be day courses to learn the basics, search for something like "grow gourmet mushrooms [cityname]"

The Radical Mycology book is the book for me: https://radicalmycology.com/ Also Paul Stamets's shop have a lot of resources: http://www.fungi.com

This is the HN post I've been waiting for all my life. I'm a software engineer by day, amateur mycologist by night.

Glad to see there's another one out there.

Out of the 2,000 or so species of mushrooms in North America, only 5 - 10 are deadly poisonous, and none grow in coffee grounds.

If you get sick it's going to be because of bacteria or mould. But you can smell if your oysters are infected. They mycelium is supposed to smell like almonds or anise if it's healthy. If it instead has a foul smell then just toss it.

That said if you want to grow them at scale, I would use shredded newspaper rather than coffee grounds. Much easier to get.

I question the statement “fresh ground coffee is harmful to plants”. Any source to that statement?

It's probably rather acidic, so it would throw of the pH balance in the soil.

I believe it is harmful to microbes, bacteria, and mold in the soil. But it is fine for plants already getting plenty of nutrients.

Possible source for how changing pH might affect soil https://vancouversun.com/news/staff-blogs/is-tap-water-killi...

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