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April 21, 2000

I learn something new everyday !!!!!!

On a trip to Mexico I saw contaminated blocks being strilized in autoclave before throwing them away. I believe it is a good idea to reduce contaminants at the farm.

September 21st 1998

If you suspect contamination source is at autoclaving, or if you wish to have a process whereby the bags can be sealed before placing into the autoclave, for example :

(a) The autoclave is far from the innoculation station,
(b) dirty atmosphere near the innoculation station

You can do the following : Install on the autoclave a high temperature resistant ball valve , a pressure regulator 0-60 psig and a source of compressed air such as one usable for a home paint sprayer. Install the regulator far enough from the ball vale so as not to be heated . adjust the pressure regulator to be about 15-18 psig. close the ball valve. fire up the autoclave as usual, when ready to cool, switch on the compressor, turn on the ball valve wait to cool, and before openning the autoclave shut off the compressor and turn off the ball valve. Bags if sealed before going into this autoclave will not bust. The reason is that the pressure is maintained in the autoclave during cooling. The pressure of 14-18 psig from the compressor, eventhough is higher than the stean pressure, will not cause the bags any harm. Of cause, the closer to 15 lbs the better.

December 5, 1999

If you want to reduce incidents of bag exploding in the autoclave, first draw a vacuum before heating with steam. The higher the vacuum, the less likely to explode bags. After vacuuming, heat and cool as usual.

Either of the above methods work well.