My Method of Pressure canning.
Only plant material is pressure canned.The produce to be canned for long term storage at room temperature is:
Washed,cut into smaller pieces, added to a large cooking pot, covered with water to make a drinkable texture. Cooked until soft, about 20 minutes. When soft, blended into a homogeneous slurry with a hand blender.The slurry is then strained through a food mill or screen usually about 2mm mesh.The residue from the food mill or screen is usually put through a Champion Juicer to recover the maximum nutrients. This product usually a small amount makes a fine soup base or can be mixed with the food mill juice.
The juice obtained is them placed in liter jars,which are placed in the pressure canner. The pressure canner, a Presto, handles 7 one liter jars per batch.The canner is set for about 50 minutes, without the rocking weight in place until steam pours vigoursly out the vent. This usually takes about 30 minutes or more.Then the weight is installed and when it starts to rock indicating 15 PSI, the 15 minute timing commences.At the end of the timing interval, heat is turned off and the pressure cooker is allowed to cool naturally.Lids are checked for seal and any not sealed are re-pressure canned with a new lid, or the jar of produce is used within a few days.I reuse the lids if not damaged and the failure rate is similar to using new lids each time, very minimal.
Water in the pressure canner is 3 liters. The gasket surface is lightly oiled by running the finger over the surface with kitchen vegetable oil. This extends the life of the gasket to years before replacement is required.The lid of the pressure canner should never be used like the lid on a normal pot. Such will overheat the gasket and dry it out, and will necessitate early replacement.
Th chosen, 15 PSI and 15 minutes, is justified as being an overkill method and the product is not considered, since it is of the same overall homogeneous texture in every case due to being blended into a slurry.
I have processed over 2000 liter jars of virtually most food produce and ingested all with no spoilage or ill effects. Use the method at you discretion.