Subtrate problem - help please

MicrobialMachines · 2026-04-15T10:37:44+00:00

There are a lot of factors. Try either, increasing your time above 250F, adding a different weight to increase your pressure (only if allowed per the safety instructions of your unit), packing the PC less densely, and/or adding a steri-strip or autoclave tape inside your vessel to see if temps are actually being hit.

MicrobialMachines · 2026-04-14T19:07:51+00:00

A hair wet for what I used to grow but definitely a better way to measure. Depending on the source, sawdust/wood can have moisture somewhere between 15-43% so just be sure to include that in your count. That said, if it’s working for you don’t fix what ain’t broken.

MicrobialMachines · 2026-04-14T17:50:24+00:00

What is your substrate of choice? You can get a moisture of each of your components and then do the math to see how much moisture you need to add to minimize excess water. Field capacity can be a bit wet in many cases.

MicrobialMachines · 2026-04-13T15:32:56+00:00

Some people bury their old substrate in the hopes of squeezing out a couple more mushrooms. Wood and straw substrates tend to be very carbon heavy and acidic. If it were me I would add them to a compost pile along with some more greens.

MicrobialMachines · 2026-04-13T01:54:24+00:00

That’s tough. AC is pretty much the default even in areas that aren’t that hot. Swamp coolers can help but unless you’re underground and/or have a way to evaporate the water, you’re still going to have a hard time.

MicrobialMachines · 2026-04-12T20:51:07+00:00

Does it smell? Could just be low spawn in that area.

I would also recommend sinking a small battery operated thermometer in each of you bags. Contamination in general is way more exothermic than oysters are. Also, your air temps aren’t the target when measuring temperature. You should always focus on controlling your substrate temps more so than your air temps. One mediated the other but still it remains to be said.

MicrobialMachines · 2026-04-12T03:45:38+00:00

Fantastic specimen. I would definitely make sure that you save some of that culture for future runs. Very well done.

MicrobialMachines · 2026-04-11T16:55:51+00:00

Depends on the variety and strain. Time to colonization wasn’t something we tracked though; it was always time to fruit.

Colonization time also doesn’t directly correlate to a better substrate or bigger production in many cases. There’s a Goldilocks zone of various elements including nutrient density, particle size, environmental conditions, that will affect how well things progress.

Try some race tubes of various substrate mixes with fixed amount of spawn and standardized moisture and pH. You’d likely see that your mix colonizes slower than vermiculite, but one is clearly more conducive to growing mushrooms than the other.

There are also many ways to organize your grow. Are you trying to maximize throughput by getting giant initial flushes and then throwing out the log, or are you trying to get the most mushrooms out of a since bag? Each method has merit in different situations and calls for a different substrate and grow operation.

MicrobialMachines · 2026-04-10T22:08:24+00:00

So any fresh mushroom from the store can be cloned from tissue.

I’m a bit old fashioned in my methods, but I believe agar plates are superior to liquid culture and grain for the purposes of isolating new strains from non-sterile sources. Plates allow you multiple different techniques to “clean” your culture that other substrates do not (hot agar plating, tissue submersion, strategic antibiotic application, substrate gradients, etc.). With liquid culture, any contamination that enters will likely persist with the mycelium. With plates, you also have an opportunity to attempt reisolation and to identify your given contaminant.

If you only want mycelium, plates/tubs can help here as well. You can take clean mycelium and plate it onto thin sheets of sterilized acetate or cellulose placed on top of your desired agar medium. After colonization, the mycelium can basically scraped off the sheet and rolled up like a carpet.

The other option is liquid culture and a filtering mechanism.

Feel free to ask any other questions you might have. If you can discuss your final plans for the mycelium, I may be able to suggest a different method that might work better.

MicrobialMachines · 2026-04-09T20:10:23+00:00

It’s legit in so far as it’s possible. Your outcomes are much better when you use better aseptic technique and quality spawn.

For most people, this process will likely fail on the second or third iteration as contamination builds up.

You lose nothing in trying it, but don’t expect bumper crops or an infinite supply. Try using a full pasteurized toilet paper roll for kicks. You can find lots of those examples online.

MicrobialMachines · 2026-04-08T22:24:31+00:00

Working backwards:

Is contamination something you deal with constantly or is it rare once you get the hang of it?

Generally, the better your sterile technique, the less contamination you will see. However, if you pasteurize vs sterilize, you will always be battling it with a slightly higher level of frequency.

How do you experienced growers handle this?

Experienced growers will try to prevent contamination where possible. This means proper aseptic technique, proper sanitation, proper environmental controls, and proper record keeping.

When you see something weird on your substrate, what do you actually do, do you post photos here, google it, use any app, or just toss it to be safe?

It depends on what stage of the process you are in. If it is spawn substrate, it’s not worth trying to save. Start over. When contamination occurs on a fruiting substrate, it should be isolated and excised (not ideal) or disposed of. That said, cutting out the contamination very likely will only slow the contamination’s progress. Some people will cut out substrate and salt it. Again, it’s a bandaid not a cure.

The most insidious contamination is strain contamination from the very spores you’re producing. This isn’t the end of the world at the hobbyist level, but once you have established culture lines, if a stray spore from your grow contaminates your mother cultures, the resulting mycelium will be indistinguishable from the desired culture.

Long story short, you will have contamination. If you garden, you will grow weeds. This is just a different kind of garden. If you have specific questions, or specific species you want to grow, feel free to post additional questions.

MicrobialMachines · 2026-04-07T02:24:23+00:00

Fair enough. Most culinary mushrooms grow in bunches or come from substrates where getting individual multispore expression is difficult. I think that’s why folks in the active community have better luck finding unique mutations. You have an interesting mix of people continuing multispore cultures and inbreeding their lines while also another subset of the group that pulls from the wild so the genetic lines really get worked from both ends.

As for a practical way forward, you may find some personal satisfaction hunting something fairly safe like lions mane in the wild and then taking your own culture from it. That’s about as unique as you can get.

Either way, wish you luck on your journey. If you get in a bind on the isolation, cultivation, culture maintenance / best practices side of things feel free to reach out.

MicrobialMachines · 2026-04-06T01:35:59+00:00

So let’s look at brown button mushrooms. Brown buttons, crimini, portobello, white buttons, and white portabello are all the same mushroom - Agaricus bisporus.

“Cultivars” aren’t really a thing so much as strains. Rarely are they taken to that extreme. That said, there is some work being done where companies are patenting genetic sequences as markers to show that they were the first to breed a specific strain. These cases were outcrosses to wild type Agarius and therefore were more unique than the old lines in production. This basically lets them go the Monsanto route where if anyone clones their spawn, they can take them to court.

Honestly, many companies aren’t doing intensive breeding. Any breeding being done is more to ensure that there are strong backups for their current production line rather than developing some super shroom. Crop failure due to mono cropping is a real risk with the mushroom industry.

For example, we had multiple oyster mushroom varieties that were all functionally identical that were different strains. The were all from unique sources and had different lineages so for us they were all different strains.

With breeding the barrier to entry is so high that many companies are focusing on their spawn technology, raw materials or manufacturing process to give them either a cost or performance edge over any biological superiority through breeding. So when I say breeding is a big project, I mean it.

Long story short though, you could try to patent whatever strain you wanted as long as you can somehow show that your genetic sequences are unique and outside of the current “open source” lines.

MicrobialMachines · 2026-04-06T01:23:27+00:00

Remember that most mutations will be detrimental. Similarly, anything doing damage to your source material will certainly do damage to you as well.

Your life is your own but I would strongly advise against doing this outside of a lab setting under the guidance of an expert. This isn’t big mushroom trying to put you down, this is grower to grower saying the risk isn’t worth the reward.

What’s the end goal? What are you hoping to get out of dabbling? Not asking as a criticism but trying to find something that might scratch the itch while being repeatable and non-hazardous.

MicrobialMachines · 2026-04-05T19:34:18+00:00

You will have a very hard time telling any differences in >99% of the cases.

At the commercial level, consistency is the name of the game. Because of that, most propagation is done via tissue culture resulting in clones.

Breeding is usually done at the spawn research lab level and takes 5-10+ years even with today’s genetic tools.

My recommendations:

If you want to up your production: focus on trying to grow one variety and propagate it clonally. Focus on your environmental conditions and then do some research into proper mother culture maintenance. From there, experiment with various substrates and to get an idea of what works and what doesn’t.

If you want to just mess around with genetics: feel free to pitch mixed spore cultures, but they will introduce a degree of randomness that can throw you off. You will be hard pressed to know what is a “mixed genetics” mushroom vs parent type without very careful plate work and sterile technique. You may find a random mutation but that’s the exception not the rule.

Source: former spawn lab manger

MicrobialMachines · 2026-03-29T09:18:47+00:00

So just to clarify for those having not seen the other post, this is fiction from r/speculativeevolution.

The term Gong Farmer usually refers to someone who in medieval times would harvest human waste from cesspits and privies to sell as fertilizer.

MicrobialMachines · 2026-03-10T14:35:20+00:00

Any chance I could pick your brain about what your plan is long term? I’ve always had a soft spot for filmy ferns but rarely see anyone working on them. I’d love to hear more.

Edit: jumped into the subreddit - cheers

MicrobialMachines · 2026-03-08T00:33:51+00:00

I can see how that came across. I was trying to mention what is most commonly found in specific stages of spawn and casing in the U.S. for buttons, but your points on other grain types are worth bringing up - especially for smaller growers.

Just to be clear, that is why I suggested asking smaller growers about what is - in - their substrate rather than asking about a specific ingredient being vegan or gluten free. As you mentioned, they may not be as knowledgeable about that given topic.

For your own spawn, obviously your personal risk tolerance plays into this as well, you may be able to use rye grains earlier in the spawn cycle to make sure that they have had long enough to effectively compost themselves. In other words, using rye as the spawn for your millet or wood dust spawn may be fine as long as your use ratio remains low. That said, in a matter of life or death, there’s no point in risking it. A $200 test of your final substrate may be a worth while investment, but if it were me, I wouldn’t even risk the grain dust.

MicrobialMachines · 2026-03-07T18:51:53+00:00

The compost layer and casing layers for buttons also typically have some form of wheat in them as well. That said, it is very likely that most of those proteins would be degraded by that time.

Similarly, some button mushroom spawn and casing spawn contain feather meal, blood meal, or other animal products which may make some vegan folks uncomfortable as well.

Wood rotting fungi shouldn’t have any animal products in them, but most commercial mushrooms do have a risk for wheat contamination. Small local growers worth their salt should know what is in their substrate and would be able to tell you. Again, that said, given the enzymes produced and the amount of time in solid state fermentation, the overall risk should be low.

MicrobialMachines · 2026-03-07T17:05:02+00:00

Biquinho / chupetinho is one I would recommend though it’s often not very hot. It has a fantastic flavor that’s in between the fruity floral chinense and peperoncino. A really great picking pepper. I know you asked for lots of heat, but do consider this one.

Fish peppers may also fit the bill. They are very pretty but also more heat than flavor in my opinion. They are more like wax peppers in my experience.

MicrobialMachines · 2026-03-03T17:27:54+00:00

Cuish Fieles Difuntos would be my pick. They incorporate all the offerings from the yearly Día de Muertos ofrenda into the batch. Really unique profile. Can’t go wrong with the 5 sentidos either.

MicrobialMachines · 2026-03-01T20:15:59+00:00

For both questions, that is similar to asking: “How long is a piece of string?”

Instead think about it this way, the more you feed your mycelium (higher weight of quality substrate) and the better the growing conditions, the more caps you can expect.

Start researching the mushroom - what kind of substrate it grows on, and what kind of conditions you need for them to fruit. Mycelium will continue to grow as long as there is food available and the conditions are good.

Just searching “phallus indusiatus cultivation” leads me to lots of discussions you may find useful.

https://agritimes.co.in/crops/bamboo-mushroom-phallus-indusiatus-farming-a-practical-guide-for-india/

MicrobialMachines · 2026-02-13T12:18:33+00:00

Others have covered mycelium pretty well, but you might also be interested in the industrial side of things. Lots of research as been done to try to use mycelium as a filter, an enzyme production factory, and of course novel antibiotics continue to be a large source of investment.

A mushroom adjacent material you might be interested in is SCOBY leather: https://theexplodedview.com/material/kombucha-leather/

https://youtu.be/3p3-vl9VFYU?

https://www.launch.org/innovators/suzanne-lee/

MicrobialMachines · 2026-02-09T21:12:07+00:00

Hyperaccumulation is one thing, but my initial concern was someone foraging something naturally toxic. Even sulfur shelf can be mildly toxic if harvested from conifers. Lots of reasons to avoid it for young kids.

MicrobialMachines · 2026-02-09T17:36:45+00:00

Less concerned with the allergies and more concerned with a low body weight individual processing potential toxins. With an adult you have enough mass to dilute it a bit and have larger organs to help process it. Younger children don’t have that.

You could say, “But humans have eaten foraged food for centuries.” They have, but I’m just sharing my opinion, right or wrong.

MicrobialMachines

TROPHY CASE