I’ve been posting this on reddit, so forgive me if you’ve already read about it…
I have long had an interest in trying to grow my own mushrooms, but recently started doing a lot of reading to learn the process. I had intended to start out growing a couple types of oysters on cut straw, but while I was collecting supplies and waited for spawn to arrive I ran across an article talking about cutting up clean cardboard, boiling it to sterilize, and seeding it with chopped mushroom stems. I figured this would be a great way to practice and see how much contamination I would get.
Besides the oysters, I wanted to also try cremini/button mushrooms. One of the local grocery stores has them in a bulk bin which appears to not be processed, and it allowed me to pick out some that looked like they came straight from the ground with obvious signs on mycelium still on the base. Great! So I set everything up, drilled some air holes in a small food container, added the cardboard and stems, and put it away in the closet. And then a couple days later I read that creminis actually want a rich mixture of manure and/or grain to grow on. Well crap…
The point was still to watch for contamination though, so I let it continue. A week passed without contamination and I was happy that it appeared I had cleaned things pretty well (and we’re talking a very hasty setup on my kitchen countertop in open air). On Sunday, I spotted some white fuzz. Oh boy, this could be it, the experiment is almost over. But then I checked on Monday… and it’s not just fuzz, I have actual STRANDS growing across the cardboard. Could it be?!?
Well, today it’s still looking pretty promising, and I’m seeing more coming out from various points in the cardboard. It’s hard to get a good look at everything because of the humidity, but today is day 12 since I set up the container and there are no greens, blues, or reds anywhere. I am hopeful, although frankly amazed at what seems to be happening.
In the meantime my oyster spawn arrived but it was less than expected so I have picked up some quart jars and am waiting to receive some rye grain. I have blue and pink oyster spawn which I will split between two jars each to expand before trying to move it to grow bags with straw. It will take a little longer than planned but I’ll get there. And I’m waiting for my container to be fully colonized with the unexpected spawn (or to see a definite sign that it is NOT mycelium) and then I’ll get that transferred to a grain jar as well.
However it goes, I’m having fun!
Cool! Good luck!! It is super fun :-)
I know that rye grain is often recommended - and it makes sense for commercial growers who can get lots of cheap rye grain and who have mastered the process of hydrating and sterilizing rye. But I have personally moved back to popcorn kernels… I can buy them at my local shop, it is easy to hydrate them to the right level, and I have less contamination. I mention this because I read that you are “waiting to receive some rye grain” - which sounds like you may have ordered it online! Consider that you can get similar or even better success with the grains that are readily available.
If you have any doubts about contamination you can post some photos and I might be able to help!
Really, popcorn? I’ve seen a couple mentions but hadn’t read anything definitive on it. What do you do to get the right hydration? From what I’ve been reading, the process for rye grain is to basically wash them, then soak for 12-24 hours, cook it for about 15 minutes, then let it dry out for a couple hours before tossing it into jars for the pressure cooker. I’m guessing the popcorn kernels are somewhat similar?
I only ordered the rye online because I was too lazy to check the local stores, and wasn’t in a huge hurry anyway. The package I got was $17 for four pounds but I figured there would be better deals if I had shopped around.
As for contamination, it doesn’t really look like mold, and certainly isn’t spreading as fast as mold does, so I’m holding out hope so far. I figure by the time it’s fully colonized I’ll be able to get some decent pictures. Or even if it’s mold. Right now I’m trying to keep it in the dark as much as possible.
Yeah! Look, here I have two jars of popcorn kernel grain spawn. On each one of the jars I put in a small piece of a King Oyster mushroom that I bought in the supermarket. I rub 70% isopropanol around the mushroom and then I tear the mushroom open and take out a tiny piece of issue from the inside. These jars were inoculated on May 16, so this is 23 days of growth:
The left one I already shook and the right one is still un-shaken.
What I mean about the hydration is that with rye grain I would often end up with grains a bit too wet and sticky, making it impossible to shake the spawn properly. The colonized grain would turn into a hard block that I had to take out with a spoon! With properly hydrated and surface-dried grain, you can shake the grains and they separate very well, making it much easier to work with them.
What I do is I buy one of these bags from the supermarket (900 g, cost is about $2.5 per kilo or $1.13 per pound):
No need to pre-soak them. I cook them in the pressure cooker for 25 - 30 minutes, starting the timer once pressure is reached without venting (this is not a sterilization step, just a cooking step). Without a pressure cooker they can be boiled for about 1 hour. Then I place them in a colander to dry - at least one hour, over night is even better. The grains should not be wet outside and they should still be firm, but it should be possible to crush them between your fingers if a moderate amount of force is applied.
Since each person has a different setup, the best way to get the right hydration for your own setup is to measure the amount of water absorbed a few times until you are happy with your procedure. You weight the grains before cooking them, and you weight them again after cooking and drying them. The increase in weight for popcorn of 40% - 70% would be a good amount of hydration.
$17 for 4 pounds of rye is quite expensive… That comes out to 4.25 / lb! Current prices I can find for my region are closer to $0.5 / lb for buying bulk. So for a mushroom farmer that buys rye in bulk from as close to the source as possible it makes a lot of sense to use rye because it is a really good grain and cheap, but when it is not sold locally and you have to order it from a specialty shop you are paying a high premium for it! Hope that makes sense!
RE: the rye grain… yeah I agree that was way expensive! I’m not doing anything in bulk though and don’t really have the space to go crazy with all this, but at the moment I haven’t even been to the local stores to see what’s available. The popcorn should be real easy to come by, though. One thing I did see, though, was adding gypsum to the water while cooking, which is supposed to help prevent the grains from sticking to each other. It looks like they’re suggesting about one tablespoon of gypsum per 5 full quart jars of dry grain. I wonder if this would help with the popcorn too?
So a couple questions here about the popcorn… If you cook it in the pressure cooker, is that done inside the mason jars or just directly in the pressure cooker with some water? I have one of the big ones for canning, so it seems like cooking directly would be more efficient just in a regular pot, and I’m guessing since you are trying to cook them at this stage you’re talking about doing it this way.
And for either method, do you add enough water to completely cover the amount of kernels you put in the pot, or do you only put a little bit of water in the bottom? And while the kernels are drying afterwards, do you do anything to protect them from picking up any contaminants?
So this morning’s viewing of my cremini spawn… whatever is growing in there is definitely expanding. I’m seeing long white strands on all four sides of the container now. I think I’ll try to hit Walmart today to find a tub I can use to make a still-air box so I have at least a little control over contamination when I transfer my various spawn to the jars. Hoping to get some jars going this weekend.
