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NecNomen
Stranger

Registered: 10/15/13
Posts: 12
Last seen: 8 years, 7 months
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LC Contamination in completely sealed un-inoculated jars?
#19222262 - 12/03/13 01:29 PM (10 years, 1 month ago) |
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Hey guys, I'm wondering if anyone else has seen this. I was getting several lids made for pf cakes/LC, pasteurizing others, making agar, and LC all in one day. I was trying to be efficient and prep all this stuff at once for the first time just starting out. I realized after I had started mixing the LC that the lids would need 24 full hours for the silicone to dry leaving me in a bit of a bind. I decided to avoid waste I would just pasteurize them with unmodified canning lids to prevent spoilage, then pasteurize again before inoculation with the new lids. The tec for LC was as follows,
1 liter h20 5g LME 1 tbsp karo 1g agar
and i wanted to add 1/4 tsp nutritional yeast but I hadn't picked any up, so I used active yeast knowing from experience it wouldn't survive the 2 hour pasteurization. I made up six liter jars.
today, after 48 hours I went to get them and re-pasteurize for inoculation. Then all had some agar and yeast sediment on the bottom, but inexplicably they were cloudy with some kind of nebulous material. Thing is the lids are sealed and still under partial vacuum, and this nebulous cloud developed pervasively in less than 12 hours (the last time I looked). I'm not aware of any microbe, even anaerobic, that produced no form of gas in it's metabolic process, and a quick search has yet to produce any exception. It would seem to be especially unlikely that such a microbe would be able to reproduce with that kind of speed.
Has anyone else ever seen this? Microbial contamination is virtually impossible as an explanation. There has been a slight temp drop, has anyone had a solution near this concentration precipitate out?
I'm going to try a few things including opening one and smelling/tasting, and re-heating, but any experiential input would be much appreciated!
Thanks in advance.
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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: LC Contamination in completely sealed un-inoculated jars? [Re: NecNomen]
#19222291 - 12/03/13 01:37 PM (10 years, 1 month ago) |
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i would have just made some agar plates , and i never wait the 24 hours for the silicone either i also wouldn't be pasturizing anything but bulk sorry for the lack of answers though bud
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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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Fred Teddy
Flying with Turkeys


Registered: 07/18/11
Posts: 208
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Re: LC Contamination in completely sealed un-inoculated jars? [Re: NecNomen]
#19235891 - 12/06/13 10:45 AM (10 years, 1 month ago) |
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Gotta question the agar in an LC recipe. Does that tek explain as to why that would benefit anything? Some agar wont melt or mix until 200 deg F. It may never dissolve at pasteurization temps. LC needs to be sterilized, not pasteurized. Also, the sugars in that recipe you stated all add up to around a whopping 7/10%, not even 1%. The popular number is somewhere around 4%. With a Karo alone LC it should be 5%-6%. If you are dead set on LC, a simple malt LC is 4gms LME, per 100ml (96ml) of water for a 4% LC. For liquified sugars - Karo, honey, etc add one or 2 additional gms per 100 ml water. Then sterilize, three Hail Mary's, and a bunch of luck. You will find that malt LC's will precipitate a bunch of stuff out of it after the PC, they are of no concern. Karo LC comes out crystal clear. While you are at it, and you apparently have agar and LME, do some no-pour jars and experiment with the world of agar. The more you hands on, the better you will get at it.
But .... if you don't have access to a pc then save these experiments until you do, or expect disappointment.
Peace, FT
-------------------- ... its all about fun and games ... and no one has poked their eye out ... yet. Peace. Disclaimer: Fact is ... Its all fiction.
Edited by Fred Teddy (12/06/13 10:47 AM)
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bodhisatta 
Smurf real estate agent



Registered: 04/30/13
Posts: 61,889
Loc: Milky way
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Re: LC Contamination in completely sealed un-inoculated jars? [Re: NecNomen]
#19235914 - 12/06/13 10:51 AM (10 years, 1 month ago) |
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Quote:
NecNomen said: Hey guys, I'm wondering if anyone else has seen this. I was getting several lids made for pf cakes/LC, pasteurizing others, making agar, and LC all in one day. I was trying to be efficient and prep all this stuff at once for the first time just starting out.
all of that stuff needs to be sterilized not pasteurized
I realized after I had started mixing the LC that the lids would need 24 full hours for the silicone to dry leaving me in a bit of a bind. if you have a pressure cooker it will cure the silicone for you once it's dry to the touch it's good enough to go in like 2-4 hours after making the lids
I decided to avoid waste I would just pasteurize them with unmodified canning lids to prevent spoilage, then pasteurize again before inoculation with the new lids. The tec for LC was as follows, pasteruization is 140-160F you're killing most bacteria, helping out the thermophilic bacteria colonize your substrate, and leaving a lot of shit ripe and ready to grow immediately in there
1 liter h20 5g LME 1 tbsp karo 1g agar agar in a LC???
and i wanted to add 1/4 tsp nutritional yeast but I hadn't picked any up, so I used active yeast knowing from experience it wouldn't survive the 2 hour pasteurization. I made up six liter jars.
today, after 48 hours I went to get them and re-pasteurize for inoculation. Then all had some agar and yeast sediment on the bottom, but inexplicably they were cloudy with some kind of nebulous material. Thing is the lids are sealed and still under partial vacuum, and this nebulous cloud developed pervasively in less than 12 hours (the last time I looked). I'm not aware of any microbe, even anaerobic, that produced no form of gas in it's metabolic process, and a quick search has yet to produce any exception. It would seem to be especially unlikely that such a microbe would be able to reproduce with that kind of speed. bacterial bloom and the pasteurization helped it along most likely
Has anyone else ever seen this? Microbial contamination is virtually impossible as an explanation. There has been a slight temp drop, has anyone had a solution near this concentration precipitate out?
I'm going to try a few things including opening one and smelling/tasting, and re-heating, but any experiential input would be much appreciated!
Thanks in advance.
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NecNomen
Stranger

Registered: 10/15/13
Posts: 12
Last seen: 8 years, 7 months
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Re: LC Contamination in completely sealed un-inoculated jars? [Re: bodhisatta]
#19242621 - 12/07/13 09:05 PM (10 years, 1 month ago) |
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Hey guys, thanks for the reply. I didn't know the silicon would set in the moist environment, good to know for next time.
I should have been more specific on how I pasteurized, since I know that term causes confusion sometimes. Understandable, it's a very general term. I don't have an autoclave that will work with the volumes I'm preparing at this point, but I do have extra time around the house so I'm steam pasteurizing @212 for at least 90 minutes. Some people call that sterilizing but it typically isn't, unless you raise the pressure/temperature as most of you do. I think it's actually unlikely that a well pasteurized (@212F) jar of media is not in fact free of any contaminates of concern in our present context, it just doesn't meet the technical standards of sterile that I'm used too referring to. I apologize for any confusion, my fault.
The sugars come to about 2.5% by mass according to my math which is not unheard of in my reading of the forums, and that is where I got the recipe. I assume the agar is to increase the viscosity and I used a recipe with it under the assumption it would help prevent turbulence during circulation on a stir plate, something that I know hinders yeast efficiency.
I opened three of the jars to add better stir bars and lids, and to test the LC before re-pasteurizing. It had no bad odor, so I tasted several samples and they tasted exactly as expected. The visual phenomenon has not increased in volume or density, and the jars I have not yet opened are still maintaining a partial vacuum. I believe it's the result of sediment in the ingredients, higher viscosity,and specific gravity that's caused the nebulous cloud.
It may be worth noting if others have used an LC recipe similar to mine that the phenomena could occur spontaneously at any point at least 48 hours after preparation, and may not signify contamination. I will of course update if time does prove results contrary to my speculation.
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