Crazy baby sterilizer for yeast idea?

Hello,

I am looking at culturing some yeast from some bottled beer and don't have a pressure cooker (this is easily rectified), but have a baby microwave sterilizer... Is it a totally crazy idea to use a baby microwave sterilizer for sterilizing perti dishes and slants?

It doesn't seem to need as long or as high a temperature as a pressure cooker (five minutes at about 212°F, compared to 15 minutes and 248°F), so logic says no, and yeast are more susceptible to infection than babies, which makes sense as they are monocellular and reproducing?

If not, then I need to make up an excuse why my little yeasties need better protection than our impending child... or get a pressure cooker cook book!

Thanks

Rob

I am not sure if these microwave "sterilizers" actually sterilize. Maybe someone with a better knowledge of microwave radiation can chime in here. The temperatures are definitely not adequate for sterilization. Only sanitizing. With baby bottles that would be adequate, but for sterile culture you need to at least start sterile.

From what I see on the internet, it is comparable to boiling which is not STERILE. How is this legal?

Reading some more, they say that anti-bacterial tablets are considered sterilization. This is completely ridiculous.

Yeah, it's not sterile... basically equivalent of boiling (unless its doing it in a pressure device). I use a pressure cooker, 15psi = about 250*F. I do this for 15 minutes and am assured everything is killed.

Thanks for confirming my suspicions... I just ran a little experiment, as I noticed there are some "steam vents" in the lid, so thought these could be sized to create a pressure with the steam flow generated (a bit like a pressure cooker or an orifice plate creating a back pressure) and measured the temperature after following the instructions and yup... 212°F, should have guessed it is certainly not built to take this kind of pressure!!

Looks like I'll be getting a nice new pressure cooker...

Thanks again

Rob

You should try to find an older model from a second-hand store, or buy a really nice new one. You want 15psi, and apparently the new ones of regular quality only go to 12psi. I found a 6 quart model, which is a little small but usable, for 7 dollars used. Just check the packaging.

I wonder if the companies making the baby gear are required to use the scientifically correct terms for sterilization vs sanitation. If not, they prob would all say sterilization just so that customers would know they meant "really, really clean".

Thanks Theredben,

The one I have my eye on seems to be OK for 15 psi. I live in Sweden so can get free shipping from UK Amazon, but alas there is no ebay... and my Swedish is not existent!

I'm sure we can think of other uses for it, like sterilising the baby stuff . I'm also sure my parents didn't sterilise much for me: "Good for you son, build up the imune system"!

Rob

Regarding sterilizing the "baby stuff", be careful what plastic you try. 250* F will melt most plastics.

Good point, thanks.

The pressure cooker I've ordered has three pressure settings, which seems good: 1) atmospheric, 2) 8 psi & 3) 15 psi.

I think I'll go with the microwave "sterilizer" for baby bottles and pressure cooker for yeast and the odd bit of cooking.

Rob