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Psilosopherr
A psilly goose



Registered: 02/15/12
Posts: 12,278
Last seen: 1 month, 10 days
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Plastic lids were loose after PC'ing. Is this normal/am I boned?
#22088342 - 08/13/15 05:38 PM (8 years, 5 months ago) |
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FYI: I simply close my jar lids until tight. I don't mess with the "leave it slightly loose and tighten it afterward" nonsense. This is my first time pressure cooking plastic lids. I had shaken the grains and taken the foil off before I noticed how loose the plastic lids were. (PC'd 3 plastic and 3 metal. the metal lids were fine)
Do plastic lids expand more than metal ones? Seems to me I might not have tightened them enough due to them having a different feel than metal ones.
The lids never came all the way off or anything, but I think they might be toast since plastic lids don't have the rubber gasket deal.
Thoughts/opinions? should I just start over?
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cronicr



Registered: 08/07/11
Posts: 61,436
Loc: Van Isle
Last seen: 2 years, 8 days
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Re: Plastic lids were loose after PC'ing. Is this normal/am I boned? [Re: Psilosopherr]
#22088361 - 08/13/15 05:44 PM (8 years, 5 months ago) |
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IME it's normal
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  It doesn't matter what i think of you...all that matters is clean spawn I'm tired do me a favor
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blackout


Registered: 07/16/00
Posts: 5,266
Last seen: 2 months, 24 days
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Re: Plastic lids were loose after PC'ing. Is this normal/am I boned? [Re: Psilosopherr]
#22088409 - 08/13/15 05:58 PM (8 years, 5 months ago) |
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Quote:
rbalzer said: I don't mess with the "leave it slightly loose and tighten it afterward" nonsense.
I do this "nonsense", and it makes sense to me, I also see sense in peoples reasoning not to do it. You have pretty much shown that there is good reason to do it. Can you seriously not see any sense in it?
Quote:
rbalzer said:Do plastic lids expand more than metal ones?
Most plastics we use will get pliable in a PC at that temperature. If you had a plastic jar and had a heavy weight hanging from it and PC'd it I would expect it to sag and deform. If it cools in this new position it will remain in it to some degree. Tightening a plastic lid tightly is putting pressure on it and pretty similar to hanging a weight on it. As it heats up the pressure can be relaxed a little and take a new shape. Then when it cools it can remain in this shape.
It can happen at steaming temp too, I had PP5 lids on peanut butter jars totally deform in a microwave after heating, to the point that they no longer could seal properly. In the microwave I used to tighten down lids as I wanted the air drawn in through the filter. In a PC I do not really worry about this, I know its the main reason people say to do it. I figure the PC is more like a SAB when its cooling down, its a moist environment and I reckon an contams that do get in the tiny hole will stick to the moisture, or at least find it very difficult to make it into lose jar lids, esp. if covered with tinfoil.
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Psilosopherr
A psilly goose



Registered: 02/15/12
Posts: 12,278
Last seen: 1 month, 10 days
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Re: Plastic lids were loose after PC'ing. Is this normal/am I boned? [Re: blackout]
#22088599 - 08/13/15 06:54 PM (8 years, 5 months ago) |
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Thanks as always cronicr 
Quote:
blackout said:
Quote:
rbalzer said: I don't mess with the "leave it slightly loose and tighten it afterward" nonsense.
I do this "nonsense", and it makes sense to me, I also see sense in peoples reasoning not to do it. You have pretty much shown that there is good reason to do it. Can you seriously not see any sense in it?
Quote:
rbalzer said:Do plastic lids expand more than metal ones?
Most plastics we use will get pliable in a PC at that temperature. If you had a plastic jar and had a heavy weight hanging from it and PC'd it I would expect it to sag and deform. If it cools in this new position it will remain in it to some degree. Tightening a plastic lid tightly is putting pressure on it and pretty similar to hanging a weight on it. As it heats up the pressure can be relaxed a little and take a new shape. Then when it cools it can remain in this shape.
It can happen at steaming temp too, I had PP5 lids on peanut butter jars totally deform in a microwave after heating, to the point that they no longer could seal properly. In the microwave I used to tighten down lids as I wanted the air drawn in through the filter. In a PC I do not really worry about this, I know its the main reason people say to do it. I figure the PC is more like a SAB when its cooling down, its a moist environment and I reckon an contams that do get in the tiny hole will stick to the moisture, or at least find it very difficult to make it into lose jar lids, esp. if covered with tinfoil.
Something to think about, I'd never heard a good reason to do it that way.
Somehow I knew I'd draw some heat by using the word nonsense
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tetherface
get in where you fit in



Registered: 10/05/14
Posts: 553
Loc: wild
Last seen: 6 years, 6 months
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Re: Plastic lids were loose after PC'ing. Is this normal/am I boned? [Re: Psilosopherr]
#22089273 - 08/13/15 09:30 PM (8 years, 5 months ago) |
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funny I just switched to plastic lids as well first round i pulled one outta the pc and shook it(holding the top like a dummy)and blammo hot ass oats all over my kitchen was pretty surprised they got that loose in the pc cycle now I've just been leaving them pretty loose and tightening them as i pull em outta the pc i used to exclusively pc with tight lids for fear of unfiltered contams entering upon cooling but now i see its not that big of an issue just as blackdust stated above
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StygianKnight
A Mushroom

Registered: 03/12/12
Posts: 2,717
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Re: Plastic lids were loose after PC'ing. Is this normal/am I boned? [Re: tetherface]
#22089486 - 08/13/15 10:50 PM (8 years, 5 months ago) |
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All mine get tightened as I pull them out of the PC. Normally there are only a few loose, but I don't see how it could hurt if quickly tightened. Plastic lids aren't air tight without a rubber ring anyway so really you're just making sure they are on tight enough that you can't bump them off.
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cronicr



Registered: 08/07/11
Posts: 61,436
Loc: Van Isle
Last seen: 2 years, 8 days
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Re: Plastic lids were loose after PC'ing. Is this normal/am I boned? [Re: blackout]
#22089499 - 08/13/15 10:53 PM (8 years, 5 months ago) |
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Quote:
blackout said:
It can happen at steaming temp too, I had PP5 lids on peanut butter jars totally deform in a microwave after heating, to the point that they no longer could seal properly.
what the hell are you doing nuking peanut butter
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  It doesn't matter what i think of you...all that matters is clean spawn I'm tired do me a favor
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cronicr



Registered: 08/07/11
Posts: 61,436
Loc: Van Isle
Last seen: 2 years, 8 days
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Re: Plastic lids were loose after PC'ing. Is this normal/am I boned? [Re: StygianKnight]
#22091119 - 08/14/15 01:01 PM (8 years, 5 months ago) |
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Quote:
StygianKnight said: All mine get tightened as I pull them out of the PC. Normally there are only a few loose, but I don't see how it could hurt if quickly tightened. Plastic lids aren't air tight without a rubber ring anyway so really you're just making sure they are on tight enough that you can't bump them off.
also
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  It doesn't matter what i think of you...all that matters is clean spawn I'm tired do me a favor
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d0urd3n
Just call me "D"

Registered: 09/15/10
Posts: 5,237
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Re: Plastic lids were loose after PC'ing. Is this normal/am I boned? [Re: cronicr]
#22091373 - 08/14/15 02:00 PM (8 years, 5 months ago) |
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I wonder if this is why lots of my plastic lids are impossible to get off with one hand. Tightened too much while hot. I think perhaps putting them fairly snug and then leaving the PC to cool overnight with foil is what I will go back to with these new sets of lids. See if it works out better as far as them getting deformed.
I guess I assumed that since they were polypropylene that I couldn't warp them. Which doesn't make sense now that I think about it.
Thanks for the info blackout
Edited by d0urd3n (08/14/15 02:00 PM)
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Psilosopherr
A psilly goose



Registered: 02/15/12
Posts: 12,278
Last seen: 1 month, 10 days
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Re: Plastic lids were loose after PC'ing. Is this normal/am I boned? [Re: d0urd3n]
#22091422 - 08/14/15 02:13 PM (8 years, 5 months ago) |
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You're telling me! Just tried to G2G and those plastic suckers were tighttt. Was all I could do to budge the last one. I'm gonna try slightly tightening after PC in the future, but with the foil off. I like my SFD's to get a chance to dry out right after PC'ing, hopefully the lack of foil will be okay.
Not that it mattered, my spawn jar had a little chunk of green in the middle. Only noticed it after I had finished up.
Probably 0% chance of success with spores being shaken around in spawn jar prior to pouring..I am having consistent bad luck with a particular species. My sterile technique has improved a lot lately, but this one species keeps fucking up.
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Kizzle
Misanthrope


Registered: 08/30/11
Posts: 9,855
Last seen: 17 hours, 26 minutes
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Re: Plastic lids were loose after PC'ing. Is this normal/am I boned? [Re: blackout]
#22091887 - 08/14/15 04:14 PM (8 years, 5 months ago) |
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Quote:
I guess I assumed that since they were polypropylene that I couldn't warp them. Which doesn't make sense now that I think about it.
There's minimum amount of pressure needed to warp them which varies based on the temperature. You don't want to over tighten the lids but they don't need to be loose either.
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