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Timestop413
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Can you have bacterial jars before they are inoculated? Plastic lids loose after PC
#28188284 - 02/15/23 08:26 AM (11 months, 6 days ago) |
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Does anyone have an example of bacteria in a jar before you inoculate it but after it’s been PC’d?
I’ve seen mold occur in jars before being used but not bacteria. Usually if I see bacteria, I notice it once the culture is colonizing and doesn’t colonize certain areas or has wet spots/uncolonized grains pushed up against the glass.
When I remove jars from PC once it hits 0 psi, sometimes lid is loose from the heat I assume (so I retighten them), not sure why this happens because I screw them tight prior to PC. Is air from the room being sucked into the jars as I remove them from PC? My jars look fine currently but I am concerned of contamination making its way into them so was thinking I should do this in front of flow hood OR wait for pc to cool longer when the lids seem to retighten. Anyone else notice this using plastic lids?
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MonkeyJesusFresco
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Re: Can you have bacterial jars before they are inoculated? Plastic lids loose after PC [Re: Timestop413] 1
#28188366 - 02/15/23 09:34 AM (11 months, 6 days ago) |
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Quote:
bacteria in a jar before you inoculate it but after it’s been PC’d
I have no pics or examples, but...
off the top of my head here are the reasons that would happen: 1) improper prepping of grain/spawn and/or improper sterilization 2) ya opened it and went digging around in the freshly sterilized grains with your dirty, shameful fingers 3) "something fucky goin on with the lid" - as alluded to in your post
the first two are kind'a self explanatory and easily resolved, but #3 seems relevant:
something fucky goin on with the lids
I am not a plastic lid kind'a guy when it comes to my spawn-jars, so I have to ask (for my own learn'n),
what is your lid situation?
are they, unmodified?
what kind of filter on them?
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Mrmeowgi
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Re: Can you have bacterial jars before they are inoculated? Plastic lids loose after PC [Re: Timestop413]
#28188368 - 02/15/23 09:35 AM (11 months, 6 days ago) |
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I have the same issue with plastic lids. They tend to loosen a bit during/after cooking. It never seems to cause a problem, though. I let them cool in the pc overnight and tighten the lids as I remove the jars. I’ve also never seen bacteria in a jar before adding culture. And I’ve let jars sit for months before opening to add culture (not recommended).
Edited by Mrmeowgi (02/15/23 09:36 AM)
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LadysKnight
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Re: Can you have bacterial jars before they are inoculated? Plastic lids loose after PC [Re: Timestop413]
#28188376 - 02/15/23 09:38 AM (11 months, 6 days ago) |
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When you run the PC, the heat expands the water in the PC, this is how it builds pressure. When it cools, it has to pull air in from the outside. This non-sterile air will get into your jars if you have no filters on the lids, or no gasket on the lids.
That said, I don't have filters or gaskets on my plastic lids and I leave them loose before the pc cycle because otherwise they can get too tight from the heat/expansion. I tighten them after inoculation. This works for me.
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Timestop413
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Re: Can you have bacterial jars before they are inoculated? Plastic lids loose after PC [Re: MonkeyJesusFresco]
#28188418 - 02/15/23 10:04 AM (11 months, 6 days ago) |
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I'm using mainstays widemouth plastic lids with a small hole on top and microppose filter
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Timestop413
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Re: Can you have bacterial jars before they are inoculated? Plastic lids loose after PC [Re: LadysKnight]
#28188422 - 02/15/23 10:08 AM (11 months, 6 days ago) |
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Quote:
LadysKnight said: When you run the PC, the heat expands the water in the PC, this is how it builds pressure. When it cools, it has to pull air in from the outside. This non-sterile air will get into your jars if you have no filters on the lids, or no gasket on the lids.
That said, I don't have filters or gaskets on my plastic lids and I leave them loose before the pc cycle because otherwise they can get too tight from the heat/expansion. I tighten them after inoculation. This works for me.
Ok that makes sense..so how are you getting by with no filters or gaskets? I don't use gaskets but I do use filters on top of the plastic lid. The plastic lid presses down against the jar rim enough to not allow anything to get in?
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LadysKnight
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Re: Can you have bacterial jars before they are inoculated? Plastic lids loose after PC [Re: Timestop413]
#28188432 - 02/15/23 10:14 AM (11 months, 6 days ago) |
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Well, technically each jar is cooling just like the PC, and have to pull in air as they cool. So it is a vector for contamination. But again, it works for me.
I started with all the safeguards, and have slowly moved backwards to less/simpler as long as it still works. YMMV based on your particular situation.
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Wintergirl
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Re: Can you have bacterial jars before they are inoculated? Plastic lids loose after PC [Re: MonkeyJesusFresco]
#28188443 - 02/15/23 10:24 AM (11 months, 6 days ago) |
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Greg
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Re: Can you have bacterial jars before they are inoculated? Plastic lids loose after PC [Re: LadysKnight]
#28188474 - 02/15/23 10:50 AM (11 months, 6 days ago) |
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Jar lids being open a bit during the PC cycle and cooldown, intentionally or as a result of the plastic lids expanding due to heat, shouldn't be a problem since the environment around them is sterile. Hell, proper microbiology labs leave their culture flasks and media bottles open a touch in the autoclave in order to equalize pressure.
There have even been successful grows using completely unmodified plastic lids left partially open during the entire colonization process.
All of this is to say, I doubt contamination before inoculation is a result of loose lids.
Edited by Greg (02/15/23 10:55 AM)
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Timestop413
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Re: Can you have bacterial jars before they are inoculated? Plastic lids loose after PC [Re: Greg]
#28188498 - 02/15/23 11:16 AM (11 months, 6 days ago) |
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Quote:
Greg said: Jar lids being open a bit during the PC cycle and cooldown, intentionally or as a result of the plastic lids expanding due to heat, shouldn't be a problem since the environment around them is sterile. Hell, proper microbiology labs leave their culture flasks and media bottles open a touch in the autoclave in order to equalize pressure.
There have even been successful grows using completely unmodified plastic lids left partially open during the entire colonization process.
All of this is to say, I doubt contamination before inoculation is a result of loose lids.
Maybe I'm overthinking it but when the PSI on the PC hits 0, its still very hot inside. Do I want to let the PC cool completely down before I open it or is it fine to open it when its at 0 psi but still warm/hot inside. Could I do this in front of flow hood? Doesn't the heat differential between the temp of the jar and the air outside of PC create a vacuum?
The reason for not wanting to let it cool down all the way is so that I can run multiple PC cycles in a day and sterilize more jars.
Edited by Timestop413 (02/15/23 11:20 AM)
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MonkeyJesusFresco
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Re: Can you have bacterial jars before they are inoculated? Plastic lids loose after PC [Re: Timestop413]
#28188545 - 02/15/23 12:01 PM (11 months, 6 days ago) |
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once mine hits 0 I take the lid off and let the jars steam off and cool down a lil but before taking 'em out
there won't be a vaccuume if your lid has a filter on it, right?
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Timestop413
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Re: Can you have bacterial jars before they are inoculated? Plastic lids loose after PC [Re: MonkeyJesusFresco]
#28188577 - 02/15/23 12:20 PM (11 months, 6 days ago) |
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Quote:
MonkeyJesusFresco said: once mine hits 0 I take the lid off and let the jars steam off and cool down a lil but before taking 'em out
there won't be a vaccuume if your lid has a filter on it, right?
possibly, the thing with the plastic jars is that they kinda loosen up after a PC cycle, so when you open the lid at 0 PSI..that plastic lid is not as tight as it was when you put it in the pressure cooker. You could probably turn it a quarter to a half turn to tighten it up again, its not so loose that it can be pulled off by lifting vertically.
I assume air would travel the path of least resistance and if the jar lid is still on the glass rim of the jar, then I would think the air would travel through the filter but upon opening the PC to notice the jar lids were loose...made me worried that non sterile air could potentially seep into them.
I plan to keep an eye on the jars I inoculated just to make sure they don't go bacterial or contam but probably best to at least open in front of a flow hood or let cool completely and then open, or both.
I'm not sure it will be a problem but better to be safe, especially if planning to expand said jars in g2g etc.
Edited by Timestop413 (02/15/23 12:22 PM)
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dowodenum
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Re: Can you have bacterial jars before they are inoculated? Plastic lids loose after PC [Re: Timestop413]
#28188884 - 02/15/23 03:29 PM (11 months, 6 days ago) |
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I won't use unmodified lids anymore because, in my mind, the air is being forced to climb through the unfiltered threads to equalize pressure. This applies both during the PC cooling with jars inside, and while cooling outside of the PC.
With a properly sized and porous-enough-but-not-too-much filter, the air takes the path of least resistance through the filter and (theoretically) the threads don't get much action even when the plastic lids expand.
This is also why I open at 0 PSI as soon as that pressure latch drops, and get in there with an Ove Glove to retighten my Ball plastic lids. And to shake before my grain clumps.
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Timestop413
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Re: Can you have bacterial jars before they are inoculated? Plastic lids loose after PC [Re: dowodenum]
#28189253 - 02/15/23 06:48 PM (11 months, 5 days ago) |
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Quote:
dowodenum said: I won't use unmodified lids anymore because, in my mind, the air is being forced to climb through the unfiltered threads to equalize pressure. This applies both during the PC cooling with jars inside, and while cooling outside of the PC.
With a properly sized and porous-enough-but-not-too-much filter, the air takes the path of least resistance through the filter and (theoretically) the threads don't get much action even when the plastic lids expand.
This is also why I open at 0 PSI as soon as that pressure latch drops, and get in there with an Ove Glove to retighten my Ball plastic lids. And to shake before my grain clumps.
Thanks for chiming in with your experience, I would not run unmodified as I have the same thought although I'm sure people do with success. Have you had any issues with the jars that you've tightened as soon as the latch has dropped?
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dowodenum
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Re: Can you have bacterial jars before they are inoculated? Plastic lids loose after PC [Re: Timestop413]
#28189444 - 02/15/23 09:46 PM (11 months, 5 days ago) |
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Plenty of issues, but nothing I couldn't attribute to my shoddy sterile technique. Mainly bacteria. I've changed too much recently, so it's too soon to tell.
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