After whipping up a batch of chili for a family reunion that we couldn't attend I was wondering what to do with it all. Annie isn't a big chili fan, and I would be eating it in my lunch until the end of the month. Finally I thought - bottle it, and blog on it. The idea to do another blog on bottling came when I was chatting with one of my daughters about her anticipated garden. She said that she might even try canning. The more I thought about this, the more I thought that it is entirely too shrouded in mystery, because for the most part, it isn't that hard.
Being one of those people that often has to tell you how the watch is made, when all you wanted was the time, I thought a little background was maybe in order. I will make it brief, and you can make it as detailed as you would like.
Anton van Leeuwenhoek discovered that there are forms of life so small that they couldn't be seen by the naked eye. He made the first microscope, and it's lens was a droplet of water. Later he made better lenses out of glass - grinding his own.
Louis Pasteur - go down to germ theory and you can read about Pasteur's experiments with broth. Basically, those experiments allowed people to see what causes food spoilage, and to come up with a simple way to preserve food. We have all been brought up knowing about microbes and how they grow and travel, and what they can do, but this was big stuff. To be able to take a nutrient broth and show that it wouldn't spoil if all the microbes in it had been killed through boiling, and that no new microbes could enter due to the design of the glassware was amazing stuff. But enough theory, time to get practical.
Canning food is nothing more killing any germ or spore in the food, and sealing it so that no germ or spore can recontaminate it. What you are canning is important - some things are harder for microbes to grow in than others, and consequently do not have to be processed as long or at as high a temperature. Let's make a list:
Easiest to hardest to preserve:
- Jams, jellies, kim chi, sour kraut and pickles are the easiest to preserve, and in some cases actually don't need any processing - they can be put into clean jars, hot from the kettle. This is a 'hot pack'. They are acidic (sour) and/or have a high sugar or salt content. It was common practice in my Grandma's kitchen to seal jams and jellies with liquid paraffin to keep out the dust. It's possible that a little mold might grow on the top of a jar of jam if you didn't do anything to prevent it, but it is unlikely that it would be anything that you couldn't scrape off - it wouldn't penetrate deeply into the jam.
- Fruit, fruit juice, salsa, spaghetti sauce, tomatoes and tomato juice etc. - these are all sour, but don't have a high sugar/salt content. Botulism microbes and/or spores can not live in an acid environment, and so these things generally can be canned successfully with water bath processing. Note: some varieties of tomatoes are 'low acid' and can allow growth of botulism. Typically, at our house we add 1 tablespoon of either lemon juice (to fruits and fruit juices or tomatoes) or 1 tablespoon of vinegar to tomatoes. We usually don't use vinegar with fruits - you could as far as canning safety is concerned, but it has a stronger flavor than lemon juice.
- Soups, meat, pinto beans - anything not acid - these things all need to have pressure processing. Pressure processing raises the temperature to above the point of normal boiling any elevation. Some pressure canners have different weight sets that allow you to pick from a variety of settings. Ours only allows 15 psi of pressure. I guess you could fiddle with the stove's heat controls to keep the pressure below 15 psi, but I don't know why you would want to. Complete directions for pressure canning are beyond the scope of the bullet point, and probably beyond my level of expertise. Here is what I do: I put about 1-1/2" of water in the bottom of the canner, add the jars (these should be at least room temperature, or hotter -preferably very hot.), put the lid on, turn the burner temperature control to just below 'HI', and let it go. When the pressure gets to 15 lbs (this is about 250 deg F), the weight will begin to rock and release steam. I turn the burner down to about half-way to HI and let it cook for 30 minutes. After 30 minutes I turn the heat off and let it cool naturally. It usually takes about 4 hours for the pressure to dissipate. I usually wait until 12 hours or so has past before removing the lid. This allows the pressure and temperature in the bottles to equalize with the ambient temperature and pressure and keeps the bottles from leaking around the seal, or worse, breaking.
Bottles: they have to be clean: hand or machine wash. It is good if they are also warm - 175 to 200 deg F. If you put hot food or liquid into a cold jar, the thermal shock can break the glass.
Lids- These also have to be clean. It is good if they are new, but not absolutely necessary. I always use new lids when I am pressure canning just because it takes to long to process, and I just don't want a problem. For jams - the easiest - I often reuse lids, especially if they are decorative.
It is good to soak the lids in boiling water. The world won't stop if you just hold new lids under a hot tap for 30 seconds, but if you are reusing lids, you should probably keep them in boiling water. This has more to do with softening the rubber seal than it does with sanitation.
Food: For water bath - non pressure canning the food must be acid- sour. This is because botulism spores can survive and grow in the absence of air and in a non-acid environment. Pressure canning kills the spores, and makes it safe to can non acid foods.
So there you go. If you have questions, put them in the comments section and I'll give you an answer, and even try to make it right. :)