Home | Community | Message Board
You are not signed in.
Sign In New Account
Forum Index Search Posts Trusted Vendors Highlights Galleries FAQ User List Chat Store Random Growery


This site includes paid links. Please support our sponsors.

Mushrooms, Mycology and Psychedelics > Mushroom Cultivation
Threaded Mode Threaded  Previous topic Previous  View all topics Index  Next topic Next 

Welcome to the Shroomery Message Board! You are experiencing a small sample of what the site has to offer. Please login or register to post messages and view our exclusive members-only content. You'll gain access to additional forums, file attachments, board customizations, encrypted private messages, and much more!

Shop: North Spore Injection Grain Bag, North Spore Mushroom Grow Kits & Cultivation Supplies   Sporeworks.EU Spores for European Microscopy   Myyco.com Golden Teacher Liquid Culture For Sale, Isolated Cubensis Liquid Culture For Sale

Jump to first unread post Pages: | 1 | 2 | 3 | 4 | 5 |  [ show all ]
Re: The Importance of Venting a Pressure Cooker or Autoclave [Re: SarahP] * 2
    #27921526 -

I think we are misunderstanding each other. Heating the PC until it’s venting water vapour establishes a pressure gradient. It does not need to be under high pressure (with the rocker/weight/regulator on) to generate a pressure gradient between the insides and outsides of the jars. Similarly, when you’re venting the PC, the water vapour coming out of the PC shows there is a pressure gradient between the inside of the PC and the outside, because the water vapour is moving out of the PC which is slightly higher in pressure than the ambient atmospheric pressure in your kitchen. I apologize if I am being unclear, I’m having issues communicating today.


--------------------
πŸ…ƒ πŸ„΄ πŸ„° πŸ„Ό    πŸ„² πŸ„» πŸ„Έ πŸ„½ πŸ„Ά πŸ…† πŸ… πŸ„° πŸ„Ώ

Extras: Filter Print Post Top
Re: The Importance of Venting a Pressure Cooker or Autoclave [Re: KROM] * 3
    #27921531 -

You are being perfectly clear, nothing difficult here to understand.

Extras: Filter Print Post Top
Re: The Importance of Venting a Pressure Cooker or Autoclave [Re: Stipe-n Cap]
    #27921534 -

Thank you kindly.


--------------------
πŸ…ƒ πŸ„΄ πŸ„° πŸ„Ό    πŸ„² πŸ„» πŸ„Έ πŸ„½ πŸ„Ά πŸ…† πŸ… πŸ„° πŸ„Ώ

Extras: Filter Print Post Top
Re: The Importance of Venting a Pressure Cooker or Autoclave [Re: KROM]
    #27921546 -

Thank you for the links, guys.

You're right, I just got it now, sorry. But that was probably me, not you.

So you're saying that 10 min venting would be enough to expel all air from inside of our jars? It feels a bit counterintuitive to me.

(Did I get it right? > After pressure starts building up, if it doesn't equalize efficiently, pressure will build up faster outside the jars and lock any air inside?)

Edited by SarahP (08/27/22 04:39 PM)

Extras: Filter Print Post Top
Re: The Importance of Venting a Pressure Cooker or Autoclave [Re: SarahP]
    #27921552 -

10 mins is a minimum requirement imo, I would recommend 15-20. This not only allows for ample time to purge but for all surfaces to slowly and evenly reach working temperatures.

Extras: Filter Print Post Top
Re: The Importance of Venting a Pressure Cooker or Autoclave [Re: SarahP]
    #27921555 -

:whathesaid:


--------------------
πŸ…ƒ πŸ„΄ πŸ„° πŸ„Ό    πŸ„² πŸ„» πŸ„Έ πŸ„½ πŸ„Ά πŸ…† πŸ… πŸ„° πŸ„Ώ

Extras: Filter Print Post Top
Re: The Importance of Venting a Pressure Cooker or Autoclave [Re: KROM]
    #27921562 -

KROM said:
Water molecules are very small, such that high pressure gas phase water should have no problems getting into the jars and displacing the air pockets within, regardless of unmodded lids and tinfoil (assuming you leave the lids loose).



Displace it where? That's the thing about being trapped.

Check out this page I was recently reading https://www.priorclave.com/en-us/2018/10/18/autoclave-sterilization-tips-avoid-foil/

Now this does't go into any kind of specifics (maybe there is a paper somewhere?) but yea it would seems that limiting access of the steam and/or trapping air is a big problem. I no longer make foil pouches that are airtight if I'm using a pouch for any reason.

I think there is a lot to letting steam freely access the thing bneing sterilized, which for instance does NOT happen at all with normal folding of spawn bags. Normally folded bags are totes airtight, steam cannot get into it.

But if you fold spawn bags with the gusset out while sterilizing there is a clear channel all the way to the grain on each end. I'll take a pic to show what I mean at some point.

edit: i didnt see all these other replies for some reason after the reply I linked to I see yalls have been discussing a lot more.


--------------------
- Sandbag Tek - How To Sterilize Spawn Bags - All About Static Pressure / Pressure Drop for DIY Flow Hoods - Sandman's LC Tek-

Marijuanaut escapes earth to cultivate - Grow-room is church temple of the new stoner breed

Edited by sandman420 (08/27/22 04:50 PM)

Extras: Filter Print Post Top
Re: The Importance of Venting a Pressure Cooker or Autoclave [Re: Stipe-n Cap]
    #27921564 -

Thank you guys, I didn't understand that the air would be expelled from inside the jars just with that normal pressure steaming (venting). Do we have enough evidence that that happens?

Also... I'm in Europe and I use a 100kPa PC (14.5 PSI), and I can't find this info anywhere: how much should I extend my PC cycle to mimic the 120m cycle @15 PSI? Is that even enough to mimic? (Or a relevant link, please?)

EDIT: Yeah, Sandman's link points in the opposite direction, but we should check that's its not just a selling line...

Edited by SarahP (08/27/22 05:37 PM)

Extras: Filter Print Post Top
Re: The Importance of Venting a Pressure Cooker or Autoclave [Re: sandman420]
    #27921600 -

I’ll have to check that link once I’m done jamming food into my face :rofl:


--------------------
πŸ…ƒ πŸ„΄ πŸ„° πŸ„Ό    πŸ„² πŸ„» πŸ„Έ πŸ„½ πŸ„Ά πŸ…† πŸ… πŸ„° πŸ„Ώ

Extras: Filter Print Post Top
Re: The Importance of Venting a Pressure Cooker or Autoclave [Re: KROM]
    #27921824 -

Thanks bod for this great post! :rockon:

Extras: Filter Print Post Top
Re: The Importance of Venting a Pressure Cooker or Autoclave [Re: KROM]
    #27921834 -

Hey, I found this on the subject. (and I don't mean to hijack the thread, this is going a little beyond topic, right?)

http://www.protocol-online.org/biology-forums-2/posts/7552.html (klinmed answers)
https://ispe.org/pharmaceutical-engineering/november-december-2013/steam-sterilization-principles-common-mistakes (check the 1st item in the "10 most common mistakes in steam sterilization" list)
https://animal.research.uiowa.edu/oar-informational-sheet-accepted-sterilization-methods ("Materials such as aluminum foil and wax paper should not be used (in autoclave sterilization) due to the steam's inability to penetrate them"
https://www.dwk.com/na/blog/lab-safety-tips-and-tricks/how-to-autoclave-glass-products (points 3,4)

Isn't this enough to consider questioning the current foiling practice, that may affect so many teks? In fact this is not about foiling, it's about allowing for proper contact between grain and pressured steam, thus allowing proper and faster sterilization (?), potentially leading to significant cost savings in energy (even if it requires adjustment in initial grain prep, right?).

(I'm also surprised that my lids may be adequate for sterilizing grain screwed tight, unfoiled as those are 13mm PTFE 0.2u filters (point 3 of last link)?


Those are jars from supermarket canned beans (I like to work with what comes on hand, if possible). I always PC them a bit unscrewed with a folded kitchen paper on top and foiled.
Also, my jars' capacity is 550ml and their base diameter is only 2ΒΎ inch, so grain should sterilize faster in them than in the regular quart jars most of you guys use, right?)

Edited by SarahP (09/17/22 04:06 PM)

Extras: Filter Print Post Top
Re: The Importance of Venting a Pressure Cooker or Autoclave [Re: SarahP]
    #27922228 -

Anyway, and I hope now on topic, couldn't this mean that "The Importance of Venting a Pressure Cooker or Autoclave" may well be quite low unless measures are taken to prevent insufficient gas exchange in this phase, enabling the expelling of all (most?) air from inside the jars before the PC is put to pressure? I mean, is venting still worth it if this isn't to be achieved?

Now I'm thinking there's a real risk of having random jars inside our pots that get low replacement of air with hot pressured steam, leading to oven-like conditions in some (many?) of them and incomplete sterilization of the grain...

I know this challenges the status quo, and its natural it creates some resistance. But if this is against your empirical experience (I mean if it's been working well enough so far) maybe this just means that venting was not that essential, with the extended time we run our PCs?

I mean, maybe some of you guys have/find relevant info about this, or someone cares to run some kind of testing on this? I surely have no conditions for that.

Extras: Filter Print Post Top
Re: The Importance of Venting a Pressure Cooker or Autoclave [Re: SarahP]
    #27922235 -

I’m not entirely sure what you’re trying to convey.  Venting the PC and ensuring gas exchange for the jars are both important. Do you guys really get an airtight/watertight seal from folding aluminium foil over the lids?

Edit: just read sandman’s link and see that even loose foil may impede steam penetration. Interesting, though I’m unfamiliar with the source. And all I got out of the other links was that loose foil allows steam penetration, but does not protect from contamination after sterilization. Admittedly, I just skimmed the articles, so I may have misunderstood.


--------------------
πŸ…ƒ πŸ„΄ πŸ„° πŸ„Ό    πŸ„² πŸ„» πŸ„Έ πŸ„½ πŸ„Ά πŸ…† πŸ… πŸ„° πŸ„Ώ

Edited by KROM (08/28/22 08:48 AM)

Extras: Filter Print Post Top
Re: The Importance of Venting a Pressure Cooker or Autoclave [Re: KROM]
    #27922252 -

Thanks for you interest, KROM

About the link you provided yesterday, it's really very interesting but I'm trying to find the best way to proceed with my 14.5 PSI PC, man.

I don't even dream about acquiring a "gravity displacement autoclave" or a "high-speed prevacuum sterilizer". Do you believe many people use these in "our" practice? How does that apply to more common PC/autoclave devices?

Edited by SarahP (08/28/22 08:55 AM)

Extras: Filter Print Post Top
Re: The Importance of Venting a Pressure Cooker or Autoclave [Re: SarahP]
    #27922254 -

Not at all, I was trying to convey that the gravity displacement autoclave works along similar principles to a pressure canner.


--------------------
πŸ…ƒ πŸ„΄ πŸ„° πŸ„Ό    πŸ„² πŸ„» πŸ„Έ πŸ„½ πŸ„Ά πŸ…† πŸ… πŸ„° πŸ„Ώ

Extras: Filter Print Post Top
Re: The Importance of Venting a Pressure Cooker or Autoclave [Re: KROM]
    #27922336 -

And are those also the principles that apply with a common PC?

I have a Taurus Ontime Rapid 10l which does 60/100kPa (max. 14.5 PSI), like this



I don't know, maybe I'm overthinking this. Maybe there's enough moisture inside the jars (in the cereal) that it equalizes without the need of much incoming water vapor. Maybe the hydrated grains are sufficiently heat conductive to make the center grains reach temperature, despite some air present?

Extras: Filter Print Post Top
Re: The Importance of Venting a Pressure Cooker or Autoclave [Re: SarahP]
    #27922352 -

Apologies, I use the terms pressure canner, pressure cooker, and PC interchangeably. And yes, I agree you’re overthinking this.


--------------------
πŸ…ƒ πŸ„΄ πŸ„° πŸ„Ό    πŸ„² πŸ„» πŸ„Έ πŸ„½ πŸ„Ά πŸ…† πŸ… πŸ„° πŸ„Ώ

Extras: Filter Print Post Top
Re: The Importance of Venting a Pressure Cooker or Autoclave [Re: KROM]
    #27922361 -

Yes, that's possible, I apologize for that too. I'm going to re-read that link of yours.

Thanks again.

Extras: Filter Print Post Top
Re: The Importance of Venting a Pressure Cooker or Autoclave [Re: SarahP]
    #27922854 -

Any pressure cooker works on same principal as a type-n gravity displacement autoclave, just not electronically controlled.

You are right that there is something to steam access and trapped air having to do with the success of sterilization. One should do there utmost to allow good steam penetration access as much as possible to achieve the best sterilization cycles, no doubt about it.

This means venting as hard as possible, not covering things with foil if not needed, not having airtight jars and bags pouches etc, etc.

For what it's worth steam penetrates the jar much better when loose lid and sideways. The air cannot be trapped when the jar is sideways.

Does that mean you gotta do all jars sideways? No but it would work best. Obs you cant pc LC sideways loose lid right.


--------------------
- Sandbag Tek - How To Sterilize Spawn Bags - All About Static Pressure / Pressure Drop for DIY Flow Hoods - Sandman's LC Tek-

Marijuanaut escapes earth to cultivate - Grow-room is church temple of the new stoner breed

Edited by sandman420 (08/28/22 04:54 PM)

Extras: Filter Print Post Top
Re: The Importance of Venting a Pressure Cooker or Autoclave [Re: sandman420]
    #27922929 -

doesn’t the water already in the jar turn to steam anyway? And if you have the bobble top pc isn’t venting still occurring?

Extras: Filter Print Post Top
Jump to top Pages: | 1 | 2 | 3 | 4 | 5 |  [ show all ]

Shop: North Spore Injection Grain Bag, North Spore Mushroom Grow Kits & Cultivation Supplies   Sporeworks.EU Spores for European Microscopy   Myyco.com Golden Teacher Liquid Culture For Sale, Isolated Cubensis Liquid Culture For Sale

Mushrooms, Mycology and Psychedelics > Mushroom Cultivation
Threaded Mode Threaded  Previous topic Previous  View all topics Index  Next topic Next 

Similar ThreadsPosterViewsRepliesLast post
* Re: Pressure Cooker Alternatives? magicpurplecow 2,617 9 05/08/00 08:10 PM
by BaldCuban
* Mirro 8QT Pressure Cooker...HELP DannyBoy 1,935 3 06/14/03 09:25 AM
by Pavement
* pressure cooker
( 1 2 3 all )		 newcultivator 6,030 42 09/07/04 12:50 AM
by seatrip
* Pressure Cooker Go BOOM?
( 1 2 all )		 Skikid16 13,641 27 09/29/02 03:15 AM
by alienated
* looks old...looks crappy....(pressure cooker) ParticleMan 1,517 12 02/10/02 09:34 AM
by ParticleMan
* Black Friday - If you dont have a Pressure Cooker, Find One!
( 1 2 all )		 BiggDaddyCane 613 21 11/27/22 07:23 PM
by PsillySeeEms
* cooling down a pressure cooker. soochi 2,296 1 08/05/03 06:29 PM
by george castanza
* Fusible Plates. I hate pressure cookers. Jared 3,186 9 03/16/04 07:26 AM
by Prisoner#1

Extra information
You cannot start new topics / You cannot reply to topics
HTML is disabled / BBCode is enabled
Moderator: Shroomism, george castanza, RogerRabbit, veggie, mushboy, fahtster, the_chosen_one, LogicaL Chaos, 13shrooms, hamloaf, cronicr, Stipe-n Cap, Pastywhyte, bodhisatta, Tormato, Land Trout, A.k.a
10,960 topic views. 10 members, 1,731 guests and 106 web crawlers are browsing this forum.
[ Show Images Only | Sort by Score | Print Topic ]
Search this thread:

Copyright 1997-2026 Mind Media. Some rights reserved.

Generated in 0.041 seconds spending 0.009 seconds on 17 queries.