Canning and Preserving

I don't provide in-depth instructions on this site, so beginners would be well served to seek out an expert.  I found the Ball Blue Book to be the most helpful guide, especially since it has step-by-step example photos for both types of canning.  Other options are your local County Extension (also called a Cooperative Extension), or sometimes your closest city college or University.  Some communities have classes offered by their recreation and parks department, and in larger cities it's often possible to find adult schools, cooking schools, or even restaurants that offer classes during off-hours. 

There are two types of canning, based on the pH level of the food being preserved.  High acid foods (fruits, soft spreads, fermented foods, and tomatoes that have had an acid added) can be preserved using the boiling-water method.  This is a great place to start, because it requires very little specialty equipment.  Basically, if you have a really large pot (large enough to cover your sealed jars with water 1-2 inches above the tops), and an oven, the only thing you'll need to buy to start canning (aside from the jars) is a jar lifter, which lets you safely remove hot jars from the canner.  It's also a straightforward canning process, and once you've done your first successful batch of anything--jam, canned fruit, marmalade, pickles--it should give you encouragement to keep going.  Low acid foods (vegetables, meats, poultry, seafood, soups, and stews) must be processed using the steam-pressure method.  This is non-negotiable.  Low acid foods cannot safely be preserved in a boiling-water canner, and there is no wiggle room in that statement.  This can be a bit more intimidating, because there tend to be a lot of safety warnings when it comes to pressure canning.  That's legitimate--nobody wants to give somebody botulism or similar--but it's important to keep in mind that you have to be just as careful with the majority of these food items when you cook with them in any other way.  Raw poultry has to be treated with care, washing hands and cutting boards and such, because of the risk of salmonella.  Chicken being preserved also has to be treated with care.  Many people have also heard horror stories about exploding pressure canners, but those stories tend to be either a) quite a few decades old, or b) told about people who bypassed safety features.  Modern pressure canners have been designed with safety in mind, and as long as the consumer follows the manufacturer's instructions, they are very unlikely to have any problems.  However, pressure canning is more of a commitment, because it does require that special equipment.  Do not attempt to pressure can with a pressure cooker or any other equipment that is not specifically made for the purpose. 

The man of the house gave me a Presto pressure canner for a Christmas gift a number of years ago.  I have used it for boiling-water canning, because if I don't use the steam pressure aspect it's just a giant pot.  I don't use it for that anymore, though, because it's so heavy and large that it's easier to just reserve it for pressure canning.  For boiling-water canning I now just use my largest stockpot.  I also own a wide-mouth canning funnel, jar lifter, and lid wand.  I do have powdered pectin, though I rarely need it for the things I preserve.  I prefer wide-mouth jars, and since the wide-mouth is always the same size regardless of jar size, using wide-mouth for all purposes means I only have to buy one size of replacement lids.  I prefer half-pints for most uses, because we are a small household. 

Canning recipes are always written for households at sea level, and it is a kitchen task that is definitely impacted by elevation, especially when it comes to pressure canning.  Anyone who lives at high altitude should understand the science, so I won't get into it.  If you are more than 1,000 feet above sea level, check the altitude charts to determine processing adjustments.  Low acid foods must be processed at 240F to destroy the bacterial spores that emit toxins, and the higher your elevation, the more pressure is needed to get the temperature up that high.  High acid foods must be processed longer, since the water will boil at a lower temperature. 

Be safe, read all instructions from pre-canning prep through post-processing instructions, know your equipment, and focus on what you're doing.  When done with care, canning and preserving can be quite a lot of fun, and for me it's one of the most satisfying tasks I do in the kitchen.  When I've started a seed inside while there's still snow out the window, nurtured it through germination and transplant, cared for that plant in the garden, gathered its bounty, and preserved it in my own kitchen, opening that jar 5 months later in the dead of winter feels fantastic.  And knowing exactly what is in every jar in the cupboard because I chose each and every ingredient is wonderful. 

P.S. You cannot home-can pureed pumpkin.  You really can't.  It's not safe.  Yes, many people have wanted to.  No, nobody should try.  The best alternative is to preserve diced hot-pack pumpkin, which you can puree upon opening the jar before using.