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bmy
Stranger to myself



Registered: 09/19/07
Posts: 222
Loc: Planet Earth
Last seen: 13 years, 11 months
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Time and temperatures - an experiment
#7459308 - 09/27/07 08:47 AM (16 years, 4 months ago) |
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Everywhere I look I see people letting their jars, LC:s, whatnot cool over night, or up to 12-24 hours. This may be for some reason other then actually just letting them cool down(?). Anyhow I thought it sounded a little overkill, so I decided to see how much time it actually took for an LC too cool down.
I heated ~250ml of water in the microwave (the toothpick is there to avoid spontaneous boiling and getting hot water all over myself) and put a probe down a hole I had drilled in the lid. Then began the waiting game.






So, after 1 hour and 20 minutes the liquid was ready for inoculation. It should be noted that I preheated the probe to avoid cooling the liquid when I put it down. It should also be noted that I had no honey/suggar in this solution. However I can't imagine that ~4% of honey would change these times much. Also, some heat may have escaped through the probe wire. I still cannot imagine that this would change the times much either. So say 1 hour and 40 minutes then. Still a hell of a lot less then overnight/12-24 hours.
And an even faster way to cool things down would be to put the jar in a cold water bath, like this:




So, is there a reason people let their stuff cool down so many hours? Have I missed something important?
(Room temperature: 24.2 C, RH: 54%)
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impeachme2
AmateurMycologist



Registered: 05/10/07
Posts: 646
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Re: Time and temperatures - an experiment [Re: bmy]
#7459638 - 09/27/07 10:15 AM (16 years, 4 months ago) |
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No, there is no other reason. Keep in mind, it will take longer to cool if you leave it in a PC. For the most part, the overnight generalization is used so people don't open up a pressurized PC too early and hurt themselves.
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bmy
Stranger to myself



Registered: 09/19/07
Posts: 222
Loc: Planet Earth
Last seen: 13 years, 11 months
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Re: Time and temperatures - an experiment [Re: impeachme2]
#7459726 - 09/27/07 10:42 AM (16 years, 4 months ago) |
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Ah, that makes sense. Good to know I haven't misunderstood something fundamental then!
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mycocurious
Mike O. Kuerias



Registered: 02/09/07
Posts: 1,265
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Re: Time and temperatures - an experiment [Re: bmy]
#7461598 - 09/27/07 06:51 PM (16 years, 4 months ago) |
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There is a very distinct "other reason". If you cause your pressure cooker to cool too quickly you'll create a vaccumn inside it - and within your jars - which will both begin "sucking" nice, filty, contaminated air from the exterior until the pressure fully equalizes...
By allowing the pressure cooker to cool very slowly, on the same burner it was heated on, allows the pressure inside the unit to equalize very slowly and does not create a vacuum...and as we all know, vacuum's suck.
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Don't mistake my tone for a "matter-of-fact" attitude. I'm just presenting what I believe to be correct, until I'm corrected... - How Myco-Curious Prepares Coir & Compost Substrates - How Myco-Curious Builds A Bulk Humidifier - How Myco-Curious Builds An Automated Greenhouse ------------------------------------ figgusfiddus said: Keep in mind that inoculating or whatever in front of a flow hood won't help your bad substrate, your bad inoculant, your bad sterile procedure, etc. etc. etc. It's not a +3 flowhood of magic, it's just a tool.
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sproket13
Stranger



Registered: 10/26/05
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Re: Time and temperatures - an experiment [Re: mycocurious]
#7461746 - 09/27/07 07:23 PM (16 years, 4 months ago) |
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i had a problem w/ my BB LC. i cooled it in a bath, and suddenly it sucked its self in. sides collapsed and it got half its size. (sure its the same, just looked different) so anyway, instead of trying to inject and getting all my spores sucked out. i wrapped it in micropore tape, then opened it to equalize. everything worked out just fine. now i use a breathing port in jars w/ polyfil. problem solved
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bmy
Stranger to myself




Registered: 09/19/07
Posts: 222
Loc: Planet Earth
Last seen: 13 years, 11 months
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Re: Time and temperatures - an experiment [Re: sproket13]
#7463233 - 09/28/07 06:32 AM (16 years, 4 months ago) |
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What I failed to realize here was that most people used pressure cookers  I just got my pressure cooker. So now I know what not to do with it It's a shame it's such a small one, 8 liters, but there are not many who sell them where I live. This one was expensive enough as it was >_< At least it can take half pints. But I think I'll have a heard time fitting a bag in there Oh well, guess I'll just have to experiment with it.
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mycocurious
Mike O. Kuerias



Registered: 02/09/07
Posts: 1,265
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Re: Time and temperatures - an experiment [Re: bmy]
#7464494 - 09/28/07 02:06 PM (16 years, 4 months ago) |
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The thing I don't like about those little pc's is that you can't have the jars upright. IMHO, the entire jar, top to bottom should be completely above the water, no water should touch the jar at any time...and those little pc's typically require you to put your jar in on it's side to make it fit and well... you get the idea.
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Don't mistake my tone for a "matter-of-fact" attitude. I'm just presenting what I believe to be correct, until I'm corrected... - How Myco-Curious Prepares Coir & Compost Substrates - How Myco-Curious Builds A Bulk Humidifier - How Myco-Curious Builds An Automated Greenhouse ------------------------------------ figgusfiddus said: Keep in mind that inoculating or whatever in front of a flow hood won't help your bad substrate, your bad inoculant, your bad sterile procedure, etc. etc. etc. It's not a +3 flowhood of magic, it's just a tool.
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Sillicybin
Registered: 02/14/05
Posts: 2,134
Loc:
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Re: Time and temperatures - an experiment [Re: mycocurious]
#7464512 - 09/28/07 02:12 PM (16 years, 4 months ago) |
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There is yet another reason to not cool your jars too quickly - CRACKING.
Especially on older jars, repetitive heat cycling causes changes in the structure of the glass. If you throw an old hot jar in a cold water bath, chances are pretty good it's going to crack, if not shatter completely.
Doing this can cause small fractures that are too small to notice, also - so the next time you go to do a PC run, you get jar(s) exploding inside your PC.
Letting the LC cool at room temperature isn't a bad idea, as long as you set the jar on a towel or other insulatory material, so it doesn't come in direct contact with a cold counter or other surface.
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bmy
Stranger to myself




Registered: 09/19/07
Posts: 222
Loc: Planet Earth
Last seen: 13 years, 11 months
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Re: Time and temperatures - an experiment [Re: mycocurious]
#7464802 - 09/28/07 04:05 PM (16 years, 4 months ago) |
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Ah, but this one can actually take 6 upright jars, they fit perfectly That's with the steamer-base inserted, which is about 1dm above the bottom. I tried to find the one with the biggest diameter to be able to fit as many jars as possible. It's 26 cm in diameter. You do the math for height 8000/((26/2)^2)*pi iirc. It's a fissler magic 8.0 btw.
About the cracking jars I completely agree. Putting them in a cold water bath is probably not the best of ideas. But room temperature and then fridge when they're down to ~40 degrees should be ok I guess(?).
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