Is this an alternative to the pressure cooker for autoclave?

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schupaul

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I am starting a yeast bank and just lack the pressure cooker. However, this is only thing that I would ever use it for. I was looking and ran across this:
41ez3FG-c-L._SL500_AA280_.jpg


Do you think something like this would be an alternative?
 
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Linky no worky...

But if it's the "autoclave in a microwave" product, someone started a thread asking the same thing last year, and noone answered, because no one had used it....
 
According to the reviews you can use any brand of baby bottle in those which is a clear indication that it is not reaching 250 degrees and is not in fact sterilizing.

Moreover, they say that contents will remain sterile if you keep the thing covered for 24 hours. If they were actually sterile, they would remain so forever.

I assume it is killing everything but spores (which boiling would do) and assuming that spores won't survive digestion. Since you aren't digesting your plates and slants but rather incubating them, you need actual sterilization and the destruction of spores.

If you absolutely do not want to buy a pressure cooker, google "tyndallization".
 
I'd also think that it is only steaming everything at boiling temp. I really don't think that plastic like that can hold the pressure needed for 250* like a pressure cooker.
 
I know that botulism spores can withstand boiling, but since I'm immediately freezing the yeast in an acidic environment I'm not worried about that.

Are there spores that can withstand boiling that can infect a beer? I know there are very few things that can even live in beer.

Is autoclaving really necessary?
 
yeah, just get a canning pressure cooker. There's lots of other stuff you can do with it too. I just made a big batch of starter wort and canned it in a bunch of pint jars, so I don't have to make it every time.
 
How long will this starter wort last canned like that. Do you have refrigerate it or use it just like any other canned good. I may be interested in this one.
 
How long will this starter wort last canned like that. Do you have refrigerate it or use it just like any other canned good. I may be interested in this one.

Canned wort can be stored at room temp like any other canned item. It will remain sterile until the seal is breached (e.g., opened, rusts out, jar cracks).

I supposed after a Very Long Time the wort could start to degrade chemically, but I haven't seen anyone put a number-of-years figure on that. I do a standard freshness rotation and I think the oldest I've used was 4mos or so.
 
Pressure cookers start pretty cheap: Manttra Aluminum Pressure Cooker - 4 qt. (24101) : Target

Even though boiling kills "most" of the beasties, If your starting from slants that will be stored, they will propogate. I cycle through my canned wort in less than 6 months as well. FDA Has a ROT of 1 year for canned fruits and vegetables, but that is more for flavor than safety.
 
Canned wort can be stored at room temp like any other canned item. It will remain sterile until the seal is breached (e.g., opened, rusts out, jar cracks).

I supposed after a Very Long Time the wort could start to degrade chemically, but I haven't seen anyone put a number-of-years figure on that. I do a standard freshness rotation and I think the oldest I've used was 4mos or so.

I can wort regularly and have used canned wort that was about 20 months old. Smelled great, worked great and no off-flavors in the finished beer.

canning wort is definitely the way to go!

canning.JPG
 
^ that is a lot of wort. lol

I just did 3 gallons. That gives me 24 pint jars or enough for 12 starters, which should last for 4-5 months. I do 3 stage starters because I've been using slants.. I take a sample from my yeast bank and mix it in a very small vessel with about 5-10 mL of starter wort. I put the opened wort in the fridge and put the small starter on a stir plate overnight. The next day, I warm up the opened wort jar and add the rest. Third day, I add the second pint. Forth day, crash cool.

If you have the money, I suggest buying a big canner. It makes things so much easier, but expect to pay $100+.
 
This is pretty dry, but it talks about using a microwave oven to kill yeast and bacteria. I think that it might be useful in yeast cultivation.

The article is seven pages long. Below is the summary.

Microwaves in the laboratory: Effective decontamination | Clinical Laboratory Science | Find Articles at BNET

OBJECTIVE: We hypothesize that microwave irradiation of certain contaminated materials typically used in a clinical laboratory or a home healthcare setting could produce efficient and effective sterilization when compared to standard autoclave methods.
DESIGN: A standard household carousel microwave oven unit used at the High setting was employed to expose certain materials that had been contaminated with either bacteria or yeast to microwaves for specific intervals of time. Following each time interval, materials were checked for effectiveness of decontamination using standard culture techniques and colony counting. Additionally, powdered media was prepared and microwave irradiated for specific times. The media was then poured into plates and checked for microbial contamination; another set of plates was examined to determine the ability of the irradiated media to support bacterial growth.

SETTING: This study was carried out at Texas Tech University Health Sciences Center in Lubbock TX.
MAIN OUTCOME MEASURE: Standard culture and colony counting techniques were used to determine the efficacy of microwave sterilization.

RESULTS: The study indicated that microwave irradiation provided effective and efficient sterilization of all materials tested. Of the bacteria studied, only E coli survived beyond 30 seconds of microwave exposure. Yeast did not survive beyond 15 seconds of microwave exposure. Swabs and gauze contaminated with bacteria or yeast were completely sterilized after 30 seconds. After three minutes in the microwave oven, powdered, prepared media was free of contamination while able to support growth when inoculated with S. aureus.

CONCLUSION: We conclude that a household carousel microwave oven unit can provide fast, effective sterilization of certain contaminated materials typically used in a clinical laboratory, student laboratory, or home healthcare setting.
 
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