Pressure Cooker question?

Mackdizzle420

Active Member
Im doin brf cakes/PF tek

And my pressure cooker is brand new not even been opened...im aware you dont need it and can do a hot bath but this is the method I've done once before and we used a PC...

The PC has a setting of 5psi, 10 psi, and maxes out at15 psi, 15 is it I cant go any higher...is that enough or does it need to be over 15 psi like 17 psi to be be fully sterile?

Me being me I like to overkill things sometimes...I kno its probably a silly question I jus want to hear other peoples input
 

Mackdizzle420

Active Member
I have no doubts that 15 psi for 90 min should sterilize small jars. My presto redlines at 20; usually try to run it around 18 for the duration. Don’t start timing until pc reaches full pressure; duration is as important as pressure.
I would kno if it didn't work later on because I would get contamination down the road wouldnt I?
 

Mackdizzle420

Active Member
I have no doubts that 15 psi for 90 min should sterilize small jars. My presto redlines at 20; usually try to run it around 18 for the duration. Don’t start timing until pc reaches full pressure; duration is as important as pressure.
This is exactly what I have16192262266408132885566842888009.jpg16192266357572617940325034135726.jpg
 
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Richard Drysift

Well-Known Member
Oh I see there’s no pressure gauge; it is set by the little weight in the middle. I have the 23qt model myself. That will work though; no worries
 

Richard Drysift

Well-Known Member
Sterilizing your grain spawn (BRF) will ensure it is clean before you inoculate but contams can still get in there during the process. Doing the inoculation inside a still air box will help reduce chances of contam but is not 100% guaranteed that will happen. That is why you do several jars. Sterile technique is just as important as sterilizing substrate. MS syringes are supposed to be sterile too but it’s very easy to get a microbe or something in the air caught on the needle when you go to inject it. Flame the needle each time and work fast inside a SAB.
 

Mackdizzle420

Active Member
Sterilizing your grain spawn (BRF) will ensure it is clean before you inoculate but contams can still get in there during the process. Doing the inoculation inside a still air box will help reduce chances of contam but is not 100% guaranteed that will happen. That is why you do several jars. Sterile technique is just as important as sterilizing substrate. MS syringes are supposed to be sterile too but it’s very easy to get a microbe or something in the air caught on the needle when you go to inject it. Flame the needle each time and work fast inside a SAB.
So the top box is gonna be my SAB im goin to make my own and use %70 iso to sanitize everything before use ill be using a flame like you mentioned for the inoculation process...my only fear is that the pressure cooker won't hold 15 psi accurately or long enough to sterilize the substrate 16192426155827119293564276280795.jpg
 

Richard Drysift

Well-Known Member
Have no fear; 15 psi should be fine at full duration of 90min. I use alcohol to wipe everything down including the jars while setting up but just before loading SAB:
Fill a spray bottle 1/2 way w/warm water and a cap of bleach, shake in 2-3 drops of antibacterial dish soap and then use that sanitize the inside of your SAB. Get the walls good & soapy and leave it for 5-10 mins to settle the air. Most contams will stick to the walls; try to work in the center. This simple technique actually helped me a lot.
 

Mackdizzle420

Active Member
Have no fear; 15 psi should be fine at full duration of 90min. I use alcohol to wipe everything down including the jars while setting up but just before loading SAB:
Fill a spray bottle 1/2 way w/warm water and a cap of bleach, shake in 2-3 drops of antibacterial dish soap and then use that sanitize the inside of your SAB. Get the walls good & soapy and leave it for 5-10 mins to settle the air. Most contams will stick to the walls; try to work in the center. This simple technique actually helped me a lot.
Your a good man Richard thank you
 

canndo

Well-Known Member
Sterilization is a relatively process.

You could sterilize In five pounds of pressure if you want to keep it there for long enough.

What is the load of the substrate? Is it heavily contaminated? What IS the substrate? Clear water water will become sterile sooner than heavily packed flour like you are.

In the first ten minutes of 15 lbs most contaminants will
Be dead. Your problem is that you must kill every single contaminant spore. There can be no exceptions.

Some species create cyst like structures that are highly persistent. If you dont believe 90 min at 15 lbs is enough you can give those hardened organisms 24 hours to germinate before you autoclave.

Why would you use that of tech if you have a cooker? At least use whole grain and larger containers.
 

Mackdizzle420

Active Member
Sterilization is a relatively process.

You could sterilize In five pounds of pressure if you want to keep it there for long enough.

What is the load of the substrate? Is it heavily contaminated? What IS the substrate? Clear water water will become sterile sooner than heavily packed flour like you are.

In the first ten minutes of 15 lbs most contaminants will
Be dead. Your problem is that you must kill every single contaminant spore. There can be no exceptions.

Some species create cyst like structures that are highly persistent. If you dont believe 90 min at 15 lbs is enough you can give those hardened organisms 24 hours to germinate before you autoclave.

Why would you use that of tech if you have a cooker? At least use whole grain and larger containers.
The only method I kno of is brown rice flour with vermiculite and the guy who taught me used a pressure cooker for 1 hour then we did the inoculation process so im doin it exactly how we did it last time...I've read reports where all that is needed is a hot water bath and a pressure cooker is not need...but me being me I jus wanna do it the way I was taught which is with a pressure cooker...I've only done this once so open to any advice you guys have...
 

curious2garden

Well-Known Mod
Staff member
Sterilization is a relatively process.

You could sterilize In five pounds of pressure if you want to keep it there for long enough.

What is the load of the substrate? Is it heavily contaminated? What IS the substrate? Clear water water will become sterile sooner than heavily packed flour like you are.

In the first ten minutes of 15 lbs most contaminants will
Be dead. Your problem is that you must kill every single contaminant spore. There can be no exceptions.

Some species create cyst like structures that are highly persistent. If you dont believe 90 min at 15 lbs is enough you can give those hardened organisms 24 hours to germinate before you autoclave.

Why would you use that of tech if you have a cooker? At least use whole grain and larger containers.
You can't kill certain spores or prions, like any of the spongiform encephalopathies even in an Autoclave or a larger pre-vac Autoclave, you have to go to Ethylene Oxide or H2O2 for terminal sterilization. For the OP @Richard Drysift gave him the right info. The chances of needing anything more than a pressure cooker is only necessary for surgical procedures.
 

Mackdizzle420

Active Member
You can't kill certain spores or prions, like any of the spongiform encephalopathies even in an Autoclave or a larger pre-vac Autoclave, you have to go to Ethylene Oxide or H2O2 for terminal sterilization. For the OP @Richard Drysift gave him the right info. The chances of needing anything more than a pressure cooker is only necessary for surgical procedures.
I feel like even if the pressure dropped to 13 14 psi it would be okay right?
 

canndo

Well-Known Member
You can't kill certain spores or prions, like any of the spongiform encephalopathies even in an Autoclave or a larger pre-vac Autoclave, you have to go to Ethylene Oxide or H2O2 for terminal sterilization. For the OP @Richard Drysift gave him the right info. The chances of needing anything more than a pressure cooker is only necessary for surgical procedures.

Prions are not spores. In fact, they are not organisms.



Nor, I believe, will you have problems in mycology with such misfolded proteins
 

curious2garden

Well-Known Mod
Staff member
Prions are not spores. In fact, they are not organisms.



Nor, I believe, will you have problems in mycology with such misfolded proteins
You can't kill certain spores or prions, like any of the spongiform encephalopathies even in an Autoclave or a larger pre-vac Autoclave, you have to go to Ethylene Oxide or H2O2 for terminal sterilization. For the OP @Richard Drysift gave him the right info. The chances of needing anything more than a pressure cooker is only necessary for surgical procedures.
 
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