largest volume of coffee grounds for oysters?

I'm getting started growing oysters on coffee grounds and I'm wondering what volume is too much. I know folks grow kits in 5-gallon buckets, but what about a 30-gallon or 50-gallon barrel? if holes were punched in a plastic barrel for respiration, could that work? silly idea? I've got access to an awful lot of coffee grounds, and it would take way too many buckets to contain it all.

Hi Tel, no expert here, but I've just been rereading Mycelium Running, and Stamets says that the game is to get your preferred species off and running ahead of the inevitable fungal and bacterial competitors. So his methods for inoculating start with small amounts of substrate. Once the substrate is 25-50 percent colonized with mycelium, then add fresh substrate. He isn't as specific about how much new substrate should be added, but reading between the lines, I conclude that doubling is a reasonable amount. He also talks about surfing the wave of mycelial expansion, by which he means that over-incubation is possible - you must transplant your growing mycelium while it is still in aggressive growth mode. By doing this consistently, you can amplify a small beginning colony into a nearly infinite number of larger colonies. I gather that with oysters, when you want fruiting, you let a colony fill its substrate, it will fruit when it has no more room for expansion.

Two weeks ago, I started some stem butts in cardboard. They are doing well, I think in another week I will be adding more cardboard. By this spring, I hope to have at least 12 good-sized colonies (a pound or so each), and I am mulling how I will continue to grow them outside.

I guess my question is if I use too large a volume, will the center be starved of oxygen, or will it start heating up and favor thermophilic organisms, or cause some other problem? I'm certainly not planning to add 50 gallons of coffee grounds to a quart of spawn or anything silly like that.

maybe nobody's tried it, though that would surprise me. I may just have to try and risk screwing it all up to find out for myself. at the worst, I'll still have a lot of material for a compost pile.

Sorry Tel, I missed your question, didn't I?

If you're trying to grow them outside, I'd spread the grounds out rather than pile them deep, as they would be in a barrel. Inside, I think I'd try a container that was flattish. Although, here's some things I found that look intriguing -

http://www.mushroom-appreciation.com/mushroom-spawn-cardboard.html
http://www.mushroommountain.com/grow_your_own/home_cultivation.asp (blewit bomb at bottom of page)

In my experience, a deep pile of coffee grounds grows mold.

I'm starting in a small unheated greenhouse. when I run out of room in there, I'll move the show outside, though hopefully still under cover. I've got a pretty steady and large supply of coffee grounds that I'm hoping to build into a steady supply of spawn and a steady supply of mushrooms and a steady supply of lovely compost. I'm sure I'll try a variety of options, including barrels and more spread out arrangements. reading about oysters eating plastic, I'm wondering how long plastic buckets and barrels will last as containers for this stuff. we'll see.

a perforated pipe down the center of the barrel may work to keep the substrate from running too low on O2 (similar to aerating a compost pile). A polyethylene tube (sleeve) ~1' thick filled with pre-sterilized coffee grounds may be better than a barrel. Hanging sleeves about 8' long from the ceiling are pretty cool

K. B. wrote:a perforated pipe down the center of the barrel may work to keep the substrate from running too low on O2 (similar to aerating a compost pile). A polyethylene tube (sleeve) ~1' thick filled with pre-sterilized coffee grounds may be better than a barrel. Hanging sleeves about 8' long from the ceiling are pretty cool

the big advantage of using plastic barrels is that I've already got a few lying around. I was thinking of doing something similar to the pipe in the center, or maybe several pipes distributed through the barrel. or perforating the barrel itself. or some combination thereof.

the polyethylene sleeve sounds fun, but I'm sort of shooting for not buying more stuff for this. I've got some spawn to start the whole thing, the coffee grounds are free, there's enough rubbish hanging around that I ought to be ale to cobble something functional together. if I happen to come across anything like that for free, though, I'll give it a shot.

I've also got a fair number of burlap bags that I'll try out. I'll try spreading mycelium onto the bags, then adding coffee grounds. I'll try adding previously colonized coffee grounds to the bags. I've got enough to try it a few different ways.

any other ideas for medium-scale cultivation on coffee grounds are very much welcome. I'm really excited about this project and impatient for it to really get going. I wish I had started a year ago. or five years ago.

Mushrooms need to be able to breathe - they need oxygen and they release CO2 just like animals do. When growing mushrooms using artificial "straw logs" (straw encased in polyethylene tubing), it has been found that logs with a diameter of over 14 inches become anaerobic in the center, and inevitably become contaminated. I would guess a somewhat similar size might apply to coffee grounds.

There is certainly no harm in experimenting, though.

Hmmm. This brings up something I've been mentally kicking around. I've noticed that most teks direct you to grow and fruit mushrooms on a homogeneous substrate. If you had a pound or so of vigorously running spawn of an aggressive nature like oysters, couldn't you mix substrates in your next step up? In this instance, I am wondering about mixing corrugated cardboard, coffee grounds and straw. Straw and cardboard would help the grounds stay aerated.

jacque greenleaf wrote:Hmmm. This brings up something I've been mentally kicking around. I've noticed that most teks direct you to grow and fruit mushrooms on a homogeneous substrate. If you had a pound or so of vigorously running spawn of an aggressive nature like oysters, couldn't you mix substrates in your next step up? In this instance, I am wondering about mixing corrugated cardboard, coffee grounds and straw. Straw and cardboard would help the grounds stay aerated.

I like this idea. been thinking similarly myself. I've already started with the cardboard, and I've got quite a bit of straw around, too. I'll add this to the list of variations to try out.