ghiajake said:

That was the original plan (160F for 4 hours) the first batch, when I accidentally cooked them for 13 hours. That batch, and the 2.5 hour batch both soured in the same amount of time after spawning. By suggesting 170F are you thinking I didn't get the sub hot enough the first two batches?

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I pasteurize all substrate and casings at 60°C(140°F) for +2 hours after reaching core temperature. If they go sour it sounds like you might be going a little wet and/or leaving them without any oxygen for too long

PuffM4gicDr4gon said:

I work with manure substrate. Just coir and manure so take this with a grain of salt.

I try for a center temp between 145-155f. 160 is technically still pasteurization, but i don't like it getting that high.

Microbes start dying above 165, but a PC at 15psi is something lije 221f. I wouldn't personally call something sterile until that temp is reached.

Also, pasteurization failure for me usually results in pin mold or trich and shows up on my sub in a week.

I'm not sure how this translates into what you're doing but extra information is always useful.

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Kloakk said:

I pasteurize all substrate and casings at 60°C(140°F) for +2 hours after reaching core temperature. If they go sour it sounds like you might be going a little wet and/or leaving them without any oxygen for too long

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Definitely not too wet. I have always had a tendency to make my subs a bit on the dry side. I don't have good grip-strength, so I hydrate my subs to the point where I have to squeeze real hard to get water to drip out. As to the oxygen, that has been something I've been debating. I do have some concerns that the bag flaps being folded over (two creases) and held down by the plastic container is somehow starving the blocks of O2. But that is only while they are in the equipment and while cooling down. After cooled, I spawn and seal like I would any other myco-bag, pushing the air out before sealing. Can't remember if it's you or one of the other guys that vac-seals subs for sous vide pasteurizing, but I'd say my subs don't go any longer without O2 than vac-sealed subs would.

Churpee Choozle said:

Ghia, how sure are you about your inoculant? And what is it, ie are you adding large amounts of LI / LC to very wet sub? Might seem like a pedantic question. But for me, too, pasteurization failure mostly results in a lot of mold.

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PuffM4gicDr4gon said:

Are you getting a sulfur smell by any chance?

If I'm storing manure sub for more than a day I always make sure it has oxygen. I usually just store it in a bucket with the lid cracked a little bit.

When I'm spawning to a tray I also poke a couple holes in the lid.

I have never brewed anything but I believe the fermentation bacteria need to grow in a low oxygen environment as well if I recall correctly.

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ghiajake said:

PuffM4gicDr4gon said:

I work with manure substrate. Just coir and manure so take this with a grain of salt.

I try for a center temp between 145-155f. 160 is technically still pasteurization, but i don't like it getting that high.

Microbes start dying above 165, but a PC at 15psi is something lije 221f. I wouldn't personally call something sterile until that temp is reached.

Also, pasteurization failure for me usually results in pin mold or trich and shows up on my sub in a week.

I'm not sure how this translates into what you're doing but extra information is always useful.

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By "partial sterilization" I meant that it has begun to kill, not totally killed. This usually starts around 170-180F. My sub is also just coir/manure. I haven't noticed any molds at all yet, but I'm not sure if that's because the fermenting bacteria keeps the molds at bay, or if the pasteurizing is working for everything except the fermenting bacteria. If there is any info I haven't already shared, I'd be glad to answer any other questions.

Kloakk said:

I pasteurize all substrate and casings at 60°C(140°F) for +2 hours after reaching core temperature. If they go sour it sounds like you might be going a little wet and/or leaving them without any oxygen for too long

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Definitely not too wet. I have always had a tendency to make my subs a bit on the dry side. I don't have good grip-strength, so I hydrate my subs to the point where I have to squeeze real hard to get water to drip out. As to the oxygen, that has been something I've been debating. I do have some concerns that the bag flaps being folded over (two creases) and held down by the plastic container is somehow starving the blocks of O2. But that is only while they are in the equipment and while cooling down. After cooled, I spawn and seal like I would any other myco-bag, pushing the air out before sealing. Can't remember if it's you or one of the other guys that vac-seals subs for sous vide pasteurizing, but I'd say my subs don't go any longer without O2 than vac-sealed subs would.

Churpee Choozle said:

Ghia, how sure are you about your inoculant? And what is it, ie are you adding large amounts of LI / LC to very wet sub? Might seem like a pedantic question. But for me, too, pasteurization failure mostly results in a lot of mold.

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Not a pedantic question. I don't use LC or LI because of that reason. Strictly grain spawn, and like I said previously, none of the fully sterilized subs I've tried with pans so far have had this issue.



After you guys saying that your normal contams with failed pasteurization are molds and not bacteria, I think maybe I'm getting the subs too hot, and that I'm compressing the blocks too tight before pasteurizing. The test bag I'm running today I'll do at 145F, and will loosen up the sub and spread it out so I can lay the bag flat on its back. This machine is no joke, so maybe it's working too well. I haven't used the internal probe with it yet because I didn't want to have to sterilize the probe after so there's no cross contamination with food, but I may have to moving forward if this test doesn't work out the kinks.

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ghiajake said:

Kinda sulfurous, kinda not. Fermenting kind of requires an acidic medium, or causes acidic medium from the fermentation. This is why I asked if adding hydrated lime to the sub would help. And yes, fermentation requires anaerobic conditions. I have a stinky suspicion (pun intended) that whatever bacteria I'm getting is coming from the Black Kow maybe being acidic. I might have to test the pH of it.

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Quote:

You could also split the substrate into smaller portions, like, instead of doing one bag of 4qts do 4 containers with 1qt, should get to 60°C(140°F) a lot faster.

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ghiajake said:

So the second batch of blocks soured in a couple days after spawning as well. I'm a bit confused on why. The first batch I did at 160F, 100% steam, for 13 hours (accidentally). The second batch was done at 155F, 100% steam, for 2.5 hours. Each block was around 2 quarts (890g) of substrate (2/3 coir, 1/3 sifted Black Kow), compressed, with the lip of the bags folded down. I then load the bags into the unit right-side up, with the plastic container upside down on top to keep the bag lips from blowing open during the process.

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ruawakeyet said:

For me, the bad smell goes away once colonized, but it doesn't smell shroomy at all.

Hindsight is right, the smell only gets worse with a few days of aging. 

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Hindsight said:

Adas said:

Looks great, shake it!

I'd liek to ask you folks if your pasteurized poo substrates start smelling a bit unpleasantly sweet after sitting for a while. Becaue mine always do. This doesn't normally cause problems, but it makes me wonder if it could be the cause of some of my recent failures. Especially with my Bunnell Cyans - recently I can't get them to pin. When I was starting with them, I could get pins in like 3 days or so. My current tub has been cased for like 2 weeks now and still nothing. I'm clueless.

Or maybe my culture just went bad? I went pretty fast through generations but anything is possible?

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No I don't notice a difference in smell after aging, though I admit I don't really smell it right out of the cooker because I keep it sealed from then until 3-7 days of aging is done. It always smells bad when I open it, but I will say that it smelled 10000x worse when I used the traditional 2-hour stove pasteurization teks in my early pan days, vs the 12 hour overnight instapot. It still smells bad but it's tolerable (the stove tek had it smelling like the worst sulfur sewer ever). Once colonized, it has a sweeter smell to it but I wouldn't say it's VERY sweet. Just not as nasty with some overtones of what a grain jar smells like (which is a tiny bit sweet).

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Baba Yaga said:

Do the fermenting/sour bags colonize at all? Manure based sub kept under somewhat low oxygen conditions does start to smell rank but it will go away with progressing colonization. This started to be discussed repeatedly when people were following Joc's advice of aging pasteurized sub for a few days to build up microbe count. Just thinking of this as a possibility as I don't see why your machine wouldn't work.


A couple of quotes:

ruawakeyet said:

For me, the bad smell goes away once colonized, but it doesn't smell shroomy at all.

Hindsight is right, the smell only gets worse with a few days of aging. 

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Hindsight said:

Adas said:

Looks great, shake it!

I'd liek to ask you folks if your pasteurized poo substrates start smelling a bit unpleasantly sweet after sitting for a while. Becaue mine always do. This doesn't normally cause problems, but it makes me wonder if it could be the cause of some of my recent failures. Especially with my Bunnell Cyans - recently I can't get them to pin. When I was starting with them, I could get pins in like 3 days or so. My current tub has been cased for like 2 weeks now and still nothing. I'm clueless.

Or maybe my culture just went bad? I went pretty fast through generations but anything is possible?

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No I don't notice a difference in smell after aging, though I admit I don't really smell it right out of the cooker because I keep it sealed from then until 3-7 days of aging is done. It always smells bad when I open it, but I will say that it smelled 10000x worse when I used the traditional 2-hour stove pasteurization teks in my early pan days, vs the 12 hour overnight instapot. It still smells bad but it's tolerable (the stove tek had it smelling like the worst sulfur sewer ever). Once colonized, it has a sweeter smell to it but I wouldn't say it's VERY sweet. Just not as nasty with some overtones of what a grain jar smells like (which is a tiny bit sweet).

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Eventually they will colonize a good portion of the blocks, but no full colonization. I usually spawn later the same day or the next after pasteurizing. After the temps drop to room temp of course. This is the last batch I spawned, and we're now a week after spawning and the grains still haven't recovered. Yet there is no molds or visible contams.

hamloaf said:

I think you said you are using black Kow?  Personally, I never trusted that’s stuff, because it’s basically floor sweepings and mixed with urine and such (presuming they haven’t changed anything about the way they package it nowadays).  That would be my uneducated guess as to bacterial vectors. 

Not sure how easy it would be for you to gather some filed aged cow, and/or horse manure, however that’s what I would consider trying.

Edit to add: some bacteria can survive pasteurization.

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ghiajake said:

That's good advice if using a water-bath method of pasteurizing, but I'm trying to figure out how to properly use this machine to pasteurize. Its a combination convection oven/zero-pressure steamer, so there is no "water temp".

I tried using glass jars the very first test run I did, but one of the jars busted due to thermal shock when I pulled them out.

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I steam pasteurize everything, some use a dehydrator, oven etc. It really doesn't matter how you achieve the right temperature, but anaerobic conditions over time will promote bacteria we don't want in our substrates or casings.

That is why I keep coming back to using a method that will get to pasteurizing temperatures quick without partial sterilization and avoid closed off containers or bags.

If you take a look at how mico zapotec pasteurize his substrate for zaps and subtrops you'll find a couple of things, first is a substrate that breathe well, straw is awesome for pans. He also makes sure that non of the substrate gets partially sterilized and he introduce oxygen during the process.

I mention this because zaps moves slow, at least compared to pans, so if his substrates can hold up for weeks during colonization where pans would rip through it in a matter of days it might be worth looking into

Im not saying you should try a different setup than what you got, but get an understanding of good pasteurization technique and why it works.

I have had good results with just coir and cow manure compost, but I find straw to really help the substrate breath, just trying to help here but if you're not seeing any mold then maybe Baba is on to something and it is your spawn that is giving you trouble and not the substrate

hamloaf said:

I think you said you are using black Kow?  Personally, I never trusted that’s stuff, because it’s basically floor sweepings and mixed with urine and such (presuming they haven’t changed anything about the way they package it nowadays).  That would be my uneducated guess as to bacterial vectors. 

Not sure how easy it would be for you to gather some filed aged cow, and/or horse manure, however that’s what I would consider trying.

Edit to add: some bacteria can survive pasteurization.

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Yeah, that's what I used... At this point I'd almost rather go with the non-manure substrates the other folks have good success with. I don't have a source for field-aged manure, so that would require making a new friend and I don't like doing that at my old age... You know, if it does have urine in it, that would explain the suspected low pH issue. Would worm castings be a good replacement for the manure, or Black Soldier Fly larva castings?