Publicité
PRESSURE CANNING METHOD:
With the pressure canning method, the jars of food are placed in 2 to 3 inches of
water in a pressure cooker and heated under pressure at a temperature of 240°F
or above for a specific length of time, which differs for every recipe . Pressure
canning can be used to can all types of food . It is also the only safe method of
canning low acid foods, which have a pH greater than 4 .6 . Low-acid canned
foods are not acidic enough to prevent the growth of the bacterium Clostridium
botulinum, which may cause botulism . To destroy the bacteria, foods must be
processed at a temperature of at least 240ºF, which can only be reached in a
pressure cooker . Processing foods under pressure at a temperature of 240ºF
during an adequate time ensures the destruction of the largest number of heat-
resistant microorganisms in home-canned foods .
Low-acid foods include all vegetables, meats, poultry, and seafood . This method
is also recommended for canning such items as soups, stews and chili .
Note: Although considered fruit, tomatoes have a pH value close to 4 .6 .
Therefore, you should typically process them in a pressure canner .
WARNING: 240ºF can only be reached in a pressure cooker/canner . Never
attempt to can low-acid foods using the boiling water bath method .
Instructions for pressure canning method:
Processing Instructions: Fill the jars . Allow the proper headspace according to
processing directions for specific foods . This is necessary so that all the extra
air will be removed during processing, and a tight vacuum seal will be formed .
To make sure that air bubbles have not been trapped inside the jar, run a bubble
freer or any plastic or rubberlike utensil around the edges of the jar, gently
shifting the food, so that any trapped air is released . After the air bubbles have
been removed, more liquid may need to be added to the jar to ensure proper
headspace .
Wipe off the rims of the jars with a clean, damp cloth . Screw on the lids, but not
too tightly — air needs to escape during processing . Set the jars of food on the
rack and lower the rack into the pressure cooker so steam can flow around each
jar . Add 2-3 inches of boiling water to the bottom of the cooker (pour it between
the jars, not directly on them, to prevent breakage) .
Put the lid on the cooker . Before you start counting the processing time, you have
to "vent" your pressure cooker . To do this, turn on your stove to a medium-high
setting and turn the pressure valve to the steam release position . You will soon
see some steam coming out of the pressure valve . Wait for ten minutes, allowing
steam to come out . After ten minutes, turn the dial to the HIGH pressure position
to seal the cooker . Begin counting down the recommended processing time as
soon as the valve starts releasing some steam again . Once pressure is reached,
keep the pressure constant by regulating the heat under the pressure cooker .
30
Do not lower the pressure by raising or lowering the heat during the processing .
Keep drafts from blowing on the pressure cooker . Fluctuating pressure causes
loss of liquid from jars and under processing .
When the processing is completed, carefully remove the pressure cooker from
the heat . If the pressure cooker is too heavy, simply turn it off .
WARNING: Let the pressure in the pressure cooker drop using the natural
release method . Do not use the cold water pressure release method for
pressure canning . Never use the automatic release method to hasten the
reduction in pressure when canning foods .
When the pressure cooker is depressurized, unlock the lid and tilt the far side
up, so the steam escapes away from you . Use a jar lifter to carefully remove the
jars from the pressure cooker . Place the hot jars on a rack, dry towels, boards or
newspaper, right side up to prevent the jars from breaking on contact with a cold
surface . Leave at least 1inch of space between the jars . Do not tighten the lids .
Allow the jars to cool, untouched for 12 to 24 hours .
BOILING WATER BATH METHOD:
The boiling water method is safe for high-acid foods such as fruits and pickles,
as well as pie filling, jam, jellies, marmalade and other preserves . In this method,
jars of food are heated by being completely covered with boiling water (212ºF at
sea level) .
Note: If you are unsure of the pH value of the foods you want to cook, we
strongly recommend using the pressure canning method .
Instructions for boiling water bath method:
Fill the pot about halfway with hot water . Turn on the burner and heat the water .
Have the water in the canner hot but not boiling to prevent breakage of the
jars when they're placed in the canner . Follow the same steps detailed in the
pressure cooker method for filling jars . When the water in the pot reaches a
rolling boil, begin counting the correct processing time . Boil gently and steadily
for the recommended time, adjusting the heat and adding more boiling water as
necessary .
Use a jar lifter to carefully remove the jars as soon as the processing time is up .
Place the hot jars right side up on a rack, dry towels, boards or newspapers to
prevent the jars from breaking on contact with a cold surface . Leave at least 1
inch of space between jars . Do not tighten the lids .
Allow the jars to cool untouched for 12 to 14 hours .
Selecting the Correct Processing Time
To destroy microorganisms in low acid foods processed with a pressure cooker,
you must:
31
Publicité
