Modern pressure canner
Are you asking about an 8-quart Fissler pressure cooker, not a canner? If so, it cannot safely be used as a pressure canner.
In order for any pressure cooker to be used for canning, it must meet three criteria:
1. Be large enough to hold at least 4 quart jars standing upright. This minimum size ensures that the canner will not heat and cool too quickly and helps maintain the high temperature needed to kill any spores of Clostridium botulinum (the bacterium that causes botulism) that might be present.
2. Be able to measure and regulate pressure (at 5, 10, and/or 15 psi), to ensure that the required temperature is maintained for the entire processing time.
3. Have a port for venting excess air from the canner before bringing it up to pressure. Any air that is mixed with the steam inside the canner will reduce the temperature. Lower temperatures are less effective at killing harmful bacteria and spores.I have attached two links for posts regarding this topic:
- from the University of Washington Extension: Safe Preserving: Canner or Cooker?
- from the National Center for Home Food Preservation: Canning in Pressure Cookers