Sterilize?

[RifeHeretic]

Instead of usign a pressure cooker to sterilize substrate, could you use a microwave?

Just a thought, get batches done faster.

Rife

[RifeHeretic]

So then a pressure cooker is not required? I did read soemthing like this online a while ago, wasnt too sure on its usefulness. Could you post how you did it?

Thanks,

Rife

[Mok]

The purpose of pressure cooking substrate is to bring the temperature above the normal boiling point of water.  When you cook something that is wet normally, its temperature never reaches any higher than 212F (100C) because when it goes over that temp, the water boils and draws away some of the heat, dropping it back down to 212 until all the water is gone, at which point it can go higher (but it's dry, so that's not good for our purposes).  Under pressure, liquids boil at higher temperatures, so your slushy mix of grain and water reaches something higher than 212F (100C).

 What that is I cannot remember, someone else will have to do the calculations, but those organisms (or endospores) that cannot be killed by mere 212F (100C) are destroyed at the higher temperature.  

Consquently, this temperature also breaks down (cooks) the proteins in meat and other foods faster than normal, which is why pressure cookers are good at preparing meals quickly.

Anyhow, cooking things in the microwave is spotty at best, think about a frozen burrito that burns on the outside and is yet frozen in the middle.  I'm not saying that people haven't had success with this method, but I would say that their rate of success is probably dependent upon the relative sterility of their kitchen, implements, and substrate material.

If you really can't afford a pressure cooker you'd probably be better off either steaming many jars once and accepting a few losses or tyndallizing.  Tyndallization involves repeated pasteurization with a couple of hours worth of intervals (This allows endospores that would not normally be destroyed by pasteurization to hatch and subsequently be susceptible to such a death, although, I've never done that so I can't say for myself that it works, but it seems to make sense).

By the way, pressure cookers can be found cheaply at thrift stores, I recently purchased a 4qt cooker (I don't have much storage space) for $2.
Ebay has many, I recently saw an electric 16qt cooker for $60.

[TroutMask]

roach is right about boiling small jars. It is done all the time. Microwave will NOT work, though it has been tried. This topic has been beat to hell at the shroomery, if you'd like more details/alternatives.

-TM

[dergheist]

Thanks for the link, it always helps to inspire me when someone does it cheaply yet effectively.  I have tried just cooled cooked brown rice instead of rice flour and it has worked well with the same results. Has anyone else tried this?  I have even started morel cultures with excellent results using the cooked rice mash as a subsitute for agar. Thanks LW very much for the morels btw.