I'm debating canning but I don't have a pressure canner. I was just wondering what the best method to can would be since I don't want to get botulism and I want the canned food to last for a long time.
Without a canner you are limited to canning high-acid foods.
Botulism spores don't die at 212F, the boiling point of water. A pressure canner boiling water at 15PSI raises the boiling point to 250F or so which will kill the spores.
The bacterium cannot grow in a high acid environment and so high-acid foods such as fruit and pickles do not need to be processed in a pressure canner. Look for recipes for such foods. As use2199 said they will involve boiling the jars for a while to kill things.
An excellent resource is the Ball Blue Book that can often be found near the canning supplies in grocery stores. It always calls for Ball products of course but it has a ton of good canning recipes and instructions.
Don't experiment. Botulism is not a fun thing. Your lips get tingly and then you die shortly aftwards.
Salsa, tomato sauce, and various pickled vegetables are typically all you can do if you want to have a shelf stable product using a boiling water bath. Nowadays, many recipes add extra acid (vinegar or lemon juice typically) to tomato products to make sure that botulism spores can not grow because tomatoes today have been breed to be sweeter than in days past.
Freeze the food or spring for the pressure canner if you want to do low acid vegetables, meat, soups or stews.
Here are the things I'd have liked to know before I tried hot water canning:
- It's not as straightforward as it sounds. In addition to a large pot of boiling water and canning jars, you'll need a special rack. You can buy a pot + rack combo, or just a rack that'll fit in a standard stockpot.
- You'll also need special tongs; as I discovered, you can jury-rig something with thick rubber gloves and bbq tongs, but you'll get boiling water everywhere and be very frustrated. Just buy a kit online, they're cheap enough.
- You'll be instructed to use the oven to sterilize the jars. You'll be instructed to use boiling water to sterilize the lids. Don't sterilize the rings that hold the lid in place; they don't touch the inside of the jar anyway, and sterilization will make them very hot when you try to screw them in.
- Everything -- EVERYTHING -- involved in the canning process NEEDS to be kept hot at all times. Crack open a window; my kitchen got very uncomfortable once there were several pots of boiling water plus the stove all going at the same time.
I don't have a pressure canner either, so whatever I have that's not safe to can, I freeze in http://www.canningpantry.com/freezer-jars-quart.html . (which I got on sale for less than three bucks for three last month)
The "Hot Water Bath" method involves completely submerging and heating jars in boiling water for 5 to 85 minutes, depending on the type and amount of food.
Be aware that this method, unlike pressurised canning, will not kill Clostridium botulinum, so it may only be used for highly acidic food (with a pH of 4.6 or less) unless the jars will be stored at low temperature (below 3 degrees C or 38 degrees F).
I am working on a related question and I have discovered that there is an industrial process for canning at atmospheric pressure called "Flame Sterilization."
Flame Sterilization works using very high temperatures directed from one side, where the can is rotated rapidly to prevent one side of the internal contents from getting too hot. This is achieved, apparently, by rolling the cans through the sterilization chamber. The process is for low or high acid foods.
Because of the lack of pressurization, smaller, more robust cans are used that can withstand the high internal pressure generated.
However, should there be some kind of failure, for example a blockage preventing the cans from running through the chamber, the batch is at risk. This means that over the years in the USA at least the Flame Sterilization process is now little used.
Apparently it used to be popular with small tinned preserved mushrooms.
What it does mean is that if this process is still being used somewhere in the world, then there is a supplier of cans intended for flame sterilization and resistant to explosion from internal pressures of 120C steam.
If you can find a supplier of cans for flame sterilization I would like to know, as this means that canning will be possible in an oil bath regulated at 120 or 130C.
I grew when there was NO pressure canners AT ALL. My Mother did EVERYTHING in huge kettle boiling water. Vegies, fruits, berries, compotes, soups,fish, meats, mushrooms. Fish, mushrooms, meats were cooked before to desire recipes, then then placed into jars and boiled inside kettle for amount of time.
We never got sick, and it all can be done.