This article is from the Food Preserving FAQ, by Eric Decker email@example.com with numerous contributions by others.
Toni <firstname.lastname@example.org> wrote:
>>I advise AGAINST using your Pressure Canner as a container to water bath
>> After 30 years of experience with canning, using both methods, I did
>>just this and spent 3 days in the hospital. I did not tighten the lid on
>>the canner and did not close the petcock. I maintained the full rolling
It is not a problem if one does not use the lid but your advice is basically
sound. BWB is usually done in an open pot so your experience is somewhat
rare - I hope.
I am truly sorry to here of your misfortune. Yes, you have touched on a FACT.
Installing the lid on ANY pressure device even without locking / closing off for
pressure WILL induce a pressure proportional to the heat induced vs the escape
rate of steam. The pressure will be quite variable but can reach up to around 3
PFB says "It has to be deep enough" That is a reference to a pot that is deep
enough for 2" coverage of jars and an additional amount for the roll of a boil.
That 2" depth of water above the jar is to assure the temperature at the top jar
of the jar is the maximum and not slightly lower as one gets closer to the open
suface. Proper BWB relies on convection and that process feeds off thermal mass
to immerse and soak the jars with heat.
Needless to say, not many pressure canners are deep enough to do quarts and
leave a good margin for safety - covers ALWAYS off.
>>which blew off at my first touch. A very painful experience. Water bath
>>canners are not expensive and worth every dime they cost.
Thank you for mentioning your experience as it is quite possible for a newbie to
make that very mistake.