Thursday, June 10, 2010

The Absolute Beginners Guide to Learning How To Cook for Survival: Part 14 Canning supplies

Whether there is a societal breakdown or not being able to preserve the food you may get cheaply at harvest time or in some other kind of windfall is a powerful way to save money.
Canning was created because Napoleon needed a way to feed his army without antagonizing the locals by eating all their food as the army passed through. Napoleon offered a X-prize to solve this problem. If you get food from a jar or a can you have to thank Nicolas Appert who won the prize after he invented a way to stuff food into a modified champagne bottle, seal it and boil it to make it safe from spoilage. Some rivals took the idea and decided to save money by skipped the boiling step, which allowed us to discover the dangers of botulism.
The most important thing we are trying to do in canning is to kill the Clostridium botulinum microorganism which produces botulism toxin which can paralyze your muscles within 72 hours, including those used for breathing. Oh, it leaves your brain and nervous system intact, so you can be wide awake the whole time. As little as 1 microgram is fatal to humans. While it can be killed at regular boiling temperatures it can form heat resistant spores. These spores cannot survive high acid environments like jams and tomato sauce. In a low acid environment the spores can survive and release the microorganism which thrives in a low-oxygen environment like a sealed jar of meat and vegetables filling it with botulinum toxins. To kill the spores the temperature of the jar needs to reach at least 240°F and the only way to make water reach that temperature is to increase the pressure.
There are several ways to preserve food all with there own kinds of specialized tools. You could improvise but it is much better to have the proper tools to make it safer and easier. And when it comes to preserving foods safer is better.
Canning foods has the potential of being really dangerous, even fatal, so follow the recipe. The best resources are the Ball Blue Book of Preserving and your local extension office.
Most supermarkets seem to carry a canning supplies in the summer at least. They even have kits with almost everything you need to get started. I'd also recommend getting the quart sized rather then the pint sized kit, you can do pints in a quart sized pot but not the other way around, we did that and trying to can 40 pints of strawberry jam takes a really long time when doing only 7 pints at a time.
There are two basic variations, water bath canning and pressure canning. Water bath is just that, the jars take a bath in boiling water. For meats and other low-acid foods a pressure canner must be used.
While the kits have almost everything you need, you may need to have a few other things like a spare set of tongs, preferably with silicone tips to grab sterilized jars and rings, since it needs to be sterilized too it needs to be silicone to withstand the boiling water without breaking down.
If you are making more then one batch another large pot to sterilize the next batch while the first is being processed is handy, but you should already have a stockpot that will do that duty.
A small pot for the lids, you need to sterilize them but not so much that the sealing compound is damaged. A small pot gives you better control and you should have this already anyway.
A timer for obvious reasons.
Towels, canning is a very wet process and lots of towels will keep things clean and dry.
Plenty of counter space. You don't really want to move a bunch of hot and wet jars into your pantry. You'll generally need to let the jars sit for several hours to seal and cool. You'll hear lots of popping as the jars vacuum seal themselves. What is happening is that you caused the everything to expand as it was heated; it also pushed out some of the air from the jars when they were in the water bath, as they cool everything shrinks including the air and that is how the seal is created. If you move it around too much while hot the seal won't hold, even with the rings.