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A Brief History of Canning
Water-Bath Canning (coming soon)
Pressure Canning (coming soon)
Some Recipes to Get You Started (coming soon)
A Brief History of Canning
When we think of home canning, our mind's eye is quick to envision neat rows of jars lining pantry shelves, safely filled with food just waiting to be opened so we can prepare a variety of tasty meals for our dear families. Canning our own food seems the epitome of the industrious homemaker, but canning did not begin as an answer to the housewife's problem of what to have for dinner. Instead, canning was developed as an answer to a question posed by war.
In the late 1700s, Napoleon Bonaparte of France was concerned that his soldiers were not being fed well when they traveled long distances from home, and he realized that they needed a reliable method for keeping food safe to eat for long periods. So he offered a cash prize to the person who could develop a dependable method of food preservation.
Enter Nicolas Appert, a French candy maker, brewer, distiller, and chef. Appert discovered that when heat was applied to food in sealed glass bottles, the food was preserved. In the early 1800s, the French navy successfully experimented with foods preserved by heat on their long voyages. They ate preserved meat, vegetables, fruit, and milk. But it would take more than 50 years to provide the reason for why the canning process worked. Finally, Louis Pasteur demonstrated that the growth of microorganisms causes food spoilage, and that sealing food into jars or cans using high heat kills these microorganisms, thus rendering the canned food safe to eat months, and even years, later.
Several years after Appert's discovery, an Englishman by the name of Peter Durand figured out how to successfully seal food in tin-coated iron cans, and in 1813 the first commercial canning factory was established in England. These cans of food were very expensive, and a person needed a chisel and hammer to open the container, but even so, the food canning industry was launched. Canned food was largely used by the military and explorers, and it wasn't until the 1920s that home canning caught on with homemakers.
In the mid to late 1800s, glass canning jars and two-piece lids came into being (Mason jars, 1858; Ball jars, 1886; and Kerr jars, 1903). And even though the canning process itself has changed little over the last two hundred years, research and trials led by unive4rsities and government agencies have honed the safety guidelines for specific foods being canned, and these are constantly being updated as needed. So even though you may have a recipe that has been handed down from your beloved grandmother or aunt, it's best to rely on the most up-to-date data available. You can probably still use that old-time favorite recipe, but you may need to change the processing time or method. For the sake of your family's safety, you'll be well advised to do so.
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Getting StartedThere are two basic canning methods--boiling water-bath canning and pressure canning. And essentially, there are two groups of foods--high-acid foods with a pH of 4.6 or lower and low-acid (alkaline) foods, with a pH of more than 4.6. High-acid foods generally use the water-bath method and low-acid foods require pressure canning at higher-than-boiling temperatures to render them safe.
Boiling Water-Bath CannersBoiling water-bath canning is used for high-acid foods such as jam, jelly, fruit butter, preserves, and marmalade; fruit pieces, fruit juice, and fruit pie filling; tomatoes, plain tomato sauce, and tomato juice (lemon juice or some other acidifier is added to tomato products to ensure that the acid level is high enough to safely can these foods with the boiling water-bath method); and pickles and relishes.
Any large pot with a tight-fitting lid will do, but water-bath canners made especially for canning foods are inexpensive and sized appropriately and are well worth the small investment. You will need a rack that sits on the bottom to keep the jars up from the floor of the pot, and the pot must be tall enough that the jars are covered by 2 inches of water with another 1 to 2 inches of air space above that. You can also use a pressure canner for water-bath canning as long as it is tall enough.
Boiling the jars of food in the water removes the oxygen. This helps form a tight seal and is sufficient to kill the mold, yeast, and bacterial cells present in the food. And even though boiling at 212 degrees doesn't kill the clostridium botulinum spores--which cause botulism, a potentially deadly toxin--the high acid levels in foods with a pH that is 4.6 or less doesn't allow the spores to grow. Therefore, the canned food is safe to consume.
Also, many people prefer to "get their feet wet" by water-bath canning before they take the plunge into pressure canning. But that's really just a matter of preference (or possibly courage!), because pressure canning is just a simple--in fact, pressure canning green beans is probably the easiest food of all to preserve.
Pressure CannersPressure canning at temperatures higher than 212 degrees is required for vegetables, meat, poultry, fish and seafood, and combination recipes that include low-acid foods. This is because the pH level is too high in these low-acid foods to prevent the growth of clostridium botulinum, which is the microorganism that causes botulism. When the spores are in an anaerobic environment (lacking oxygen, as happens to jars of food that are canned) they are able to grow and produce deadly levels of botulism toxin. Therefore, pressure is needed to raise the temperature, and pressure canning does that, raising the temperature inside the container to 240 degrees. When correctly processed for adequate periods of time, the botulinum spores are eliminated and the canned food is safe to store and eventually eat.
Unlike a water-bath canner, you'll need to invest in a specially made pressure canner. And while the purchase price of a pressure canner isn't small, this is an investment that will last you for many years when properly maintained.
There are basically two types of pressure canners--those that use a gasket to close and seal the canner lids after they have been locked into place (such as the Presto brand), and those that are "gasketless" and seal by use of heavy-duty screws that tighten the locked lid to the body of the canner (such as the All-American). The gasket canners generally cost substantially less than the gasketless types, but you will need to replace the gaskets every year or so, depending on how much you use it. Gaskets cost less than $10, so this is a small additional expense, and with the money you saved on the purchase price compared to the gasketless types, you will still be ahead even after many years of use.
In my part of the world, I can currently buy a Presto (uses a gasket) canner for $88.60. It will hold 7 quart jars or about 20 pint jars. An All-American that will hold the equivalent number of jars costs $209.99. As you can see, there is a very large price difference. But if your budget can handle the higher price, do you research and decide for yourself if the All-American is right for you. I personally have both kinds: 2 Presto canners and 1 All-American. I love and use them all, depending on what particular food I'm canning and how much I have to can.