did a little googlin' and came up with explanations of the two main kinds of preserving....water bath method and pressure canning...I have read that pressure canning at 10 PSIG will take the temperature inside to 240F
Water Bath Method
The water bath method of canning will heat your produce to the temperature of boiling water which is 212°F, therefore low acid vegetables (all vegetables excluding tomatoes) should be processed only using a pressure canning method.
Items needed:
Water bath canner: A large, deep pan with a good, tight fitting lid will work fine. Just make sure it is deep enough to completely submerge the size of jar chosen.
Wire rack to hold the jars off the bottom of the pan
Tongs with a large enough opening for the jar lids
Oven mitts and cooling racks
Timer
Insert the rack into the bottom of your canning pot. Begin by filling the canning pot about halfway with boiling water. Add the jars to be processed making sure to set them firmly onto the rack with sufficient room between to keep the jars from touching each other. Add additional boiling water making sure to cover the jars by at least 2 inches of water. Don’t pour the water directly onto the jars, but add it carefully into the side of the pot.
Cover the pot with a tight lid and bring the water to a full rolling boil. Depending on the length of time to process (according to your recipe), set your timer. Reduce the heat under the pot to maintain a rapid boil. Watch the water level and add more boiling water during the timing process as needed. When the timer goes off, use the tongs and remove the jars from the water immediately. Set the jars onto a thick layer of towels or a cooling rack leaving space between the jars and allow to completely cool. Tighten the seals if necessary before storing.
Pressure Canning
Items needed:
Pressure canner with steam vent
Wire rack to hold the jars off the bottom of the pan
Tongs with a large enough opening for the jar lids
Oven mitts and cooling racks
Timer.
Begin using the same process as the water bath by adding first the boiling water, then the jars onto the rack and then filling the pan with additional water to cover the jars by at least 2 inches. Firmly attach the pressure cooker lid and place the pressure cooker over high heat. Bring it to a high steam and let the steam exhaust for 10 minutes. Close the vent when the steam coming from the jet is nearly invisible.
When you have reached 8 pounds of pressure, lower the heat slightly. Let the pressure continue to rise until you have reached 10 pounds. At this point, start your timer and hold the 10 pounds of pressure for the entire process. If you have problems maintaining 10 pounds of pressure, turn up the heat, repressurize to 10 pounds and restart the timing process.
When the timer goes off, remove the pressure cooker from the heat and let it cool completely. (Do not pour cold water onto the pot to speed up the cooling process!) When the pressure returns to zero, open the vent and then carefully open the lid keeping it slanted away from you to prevent a steam burn. Remove the jars from the cooker using the tongs and set aside to cool.
Tips and Tricks:
Push on the seal and make sure it is down tight. If it pops up, the seal didn’t take which means the canning process didn’t work properly. If you choose a porcelain lined cap jar, you will need to wet the rubber ring before you fit it against the top of the jar. Firmly screw on the cap and then back it off one quarter turn. Screw the cap on tightly after processing. Be sure and date your jars before storage. Properly home-canned fruits and vegetables can have a long shelf life as long as the seal remains intact.
from this link:
http://www.essortment.com/food/homecanningwat_shho.htm
. We use similar pans to decrease cooking time 
.