FlytrapCare Carnivorous Plant Forums

What PSI should I use for sterilization with a bigger "Presto" pressure cooker 15 PSI or less ?

I always use 15 PSI for 15 minutes. I have the larger 23 quart Presto cooker. Seems to work great.

15psi; no less, (no more either) and 15 to 20 minutes is long enough for standard 25-30ml media in baby food jars.
I go 20 minutes. Watch the stove, as the pressure can creep up to 16 or more; that's getting pretty hot.

I love My big PRESTO !


Gary

15 psi produces 121 degrees C boiling (at sea level), which is standard sterilisation temperature. The timing depends on the amount of liquid in the TC containers (obviously the more there is the longer it takes to come up to temperature).
If you live at altitude, then the temperature will be less and you compensate by boiling for longer.
It's better to use the standard, which works, and to err on the side of a little too long, than to risk contamination, IMO.