Tomato Juice Just Out of Pressure Canner

I have an All American pressure canner, model 921.  I like to process my tomato products in the pressure canner because the processing time is less which makes a difference as to how many times the canner can run in a day.  The process time for tomato juice in a boiling water bath canner (BWB) is 40 minutes for 1 L jars but only 15 minutes using the pressure canner (PC).   The pressure canner is more energy efficient as I can process a larger number of jars at a time.  The PC only uses 3 L of water per load in comparison to the BWB canner that uses several L of water.

Tomato products are healthier when pressure canned.  Pressure canning increases the antioxidant properties of lycopene.  Now a pressure canner is quite easy to operate.  There are safety features built in to prevent over pressurizing.  As with any stovetop cooking, the pressure canner should not be left unattended.  When filling jars, it is important to leave a 2.5 cm (1 in) headspace.  Most seal failures and/or liquid loss when pressure canning are due to insufficient headspace.  Heat the water in the pressure canner to avoid thermal shock before adding the filled jars. Secure the lid per manufacturer's instructions then vent for 10 minutes.  Venting allows any trapped air in the jars to escape.  In a BWB canner the temperature is 100ºC (212ºF), just enough to kill bacteria, yeasts and molds in high acid foods (eg. fruits, jams, pickles).  The food does not get hot enough in the jars to boil.  The processing temperature in a PC is 116ºC (240ºC), enough to kill bacteria, yeasts, molds and destroy any botulinum toxin that may be present in low acid foods (eg. vegetables, meats, soups).

Foods taken from the PC are usually still boiling in the jar as seen in the video I took of tomato juice just out of the canner.  It is very important to not tilt the jars when removing them as that can cause the contents to erupt, leaking hot liquid everywhere creating a rather dangerous situation.  Do not put the hot jars directly onto the countertop.  Use cork trivets or t-towels to sit the jars on to prevent thermal shock.  It is very important to not adjust the rings unless you are using glass inserts or Tattler lids.  Do not adjust the rings if using the metal single use lids.  Jars should be left undisturbed for 24 hours then remove the rings and check the seal.  Wash and dry the jars and rings.  Rings can be replaced loosely on the jars for storage if desired.