In a word - NO. Pressure cookers have less metal, are
smaller in diameter, and use less water than
pressure canners. The result is that the heat-up
and cool-down times will be less than for the standard
pressure canner. These heating and cooling times
are part of the total processing time that was determinedin lab testing to establish
a reasonable margin of safety for low-acid foods.
If the heating and cooling periods are shortened, then the process time at pressure may not be enough to destroy targeted microorganisms and provide a safe product. If the food is underprocessed, low-acid canned foods are unsafe and can result in foodborne illness, including botulism poisoning, if consumed.
During early years of canning in the 1940s, the new pressure saucepans were considered an alternative to large canners. It was thought that adding 10 minutes to the process times used by standard canners , that would be enough to keep food safe. That proved not to be the case, as pressure cookers came in several sizes and they were not all adequately tested. In addition, the way heat penetrates through food during the process is affected partly by the composition of the food, and not all foods and styles of preparation were tested back then. USDA published research in the late 1980s recommended not use pressure cookers for home canning.
Even though some manufacturers advertise their
brand of pressure cooker as acceptable for use as
a pressure canner, canning experts don't agree
Some manufacturers may offer process directions for pressure cookers. Consumers using this equipment will need to discuss processing recommendations with those manufacturers; the USDA and National Center for Home Food Preservation recommendation is to not use them for canning with our processes.
To be considered a pressure canner for USDA processes, the canner must be equipped with a wire canning rack and be able to hold at least four quart-size jars. There is no method to accurately convert processes intended for use with a regular pressure canner to ensure safety when canning in other types of equipment.
November 7, 2006, National Center for Home Food Preservation
MSU University News; August 02, 2002 -- Updating
Some people may think that any recipe can be
canned at home, but that is not the case. You cannot
whip up a batch of your favorite soup, pour it into
canning jars, drop them into a canner and then serve
it up without placing your family at risk of food
poisoning. Safe canning recipes are thoroughly evaluated
in a food testing lab where the ingredients are
tested for pH factors that will determine
the correct processing time.
are many chances for creativity in cooking, but
canning is not one of them,” says Paul. Safe recipes
require testing to prevent botulism. So, even though
its tempting to try home-canning your special
soup or sauce, she encourages everyone to play it
safe and stick with tested recipes from reliable
sources. It is not safe to guess on what processing
time and pressure to use.
Sources on canning typically
very widely. Someone might still be using grandma’s
high school, domestic-science textbook, copyright
1918. Maybe you have an old USDA pamphlet dating
from the 1940s or your mom's favorite heirloom recipes. Putting Food By, first published
in 1973 is also still found in rummage sales and
thrift stores. All of these sources were reputable
in their day, but they are considere4d unsafe by
today's standards. Everyone wants to know, “What’s
wrong with them now?”
The USDA dramatically changed the canning guidelines
and instructions in 1989 to incorporate the current,
modern methods and improvements in food safety, so be sure
your recipes are current and dated after that year.
Food preservation is more
precise, and therefore much safer than it was years ago. The
most accurate, up-to-date, and dependable guidelines
are in the current bulletins put out by the USDA,
available free or at a small cost from your local county
extension office. Read these pamphlets carefully,
and follow their instructions to the letter.
Canning summer produce is a family tradition
for some—for others, it may be a first attempt.
But either way, creativity and canning aren’t
a safe combination, says Lynn Paul, a food and nutrition
specialist at Montana State University Extension.
While many people may want to follow in the
old heirloom canning recipes used by their grandparents,
but canning requires current, tested recommendations
and the right type of equipment. These recommendations
are based on the food safety and quality, says Paul,
but safety is by far the top priority.
Finally, Paul notes that what may seem to be
a daunting list of do’s and don’ts is really meant
to provide tasty and safe food. “Learn what you
need to know and have fun this summer canning your
Tomato canning recipes now require lemon juice
or citric acid because some varieties of tomatoes
may have lower acid levels than those we used in
the past. See more about acidification.
Paraffin wax seals are no longer recommended
because they will not prevent mold growth in jams
and jellies. Use canning jars with seals and lids,
and follow the directions from a recommended recipe.
Don’t use microwaves for home canning, even though
you may find a few microwave-canning recipes in
magazines. Microwaves can be extremely dangerous,
especially with low-acid foods, because botulism
bacteria could survive. Other unsafe canning methods
include crockpots, ovens, dishwashers, open-kettle canning (where food
is heated and poured into jars).