Let’s talk a bit about the history of food preservation. Food has been around since before man. In Genesis, we read that God created the trees, and vegetation on day 3, and man was created on day 6. (Genesis 1:11, 27) So, it goes without saying that there has been a time that we have had to preserve that food in some way or another.
Ancient times used more salting methods because well, electricity hadn’t been invented yet and salt preserves foods by creating a hostile environment for certain microorganisms. Within foods, salt brine dehydrates bacterial cells, alters osmotic pressure and inhibits bacterial growth and subsequent spoilage. Salting fish made long-range explorations possible in the age of sailing ships.
According to In a Cajun Kitchen,
The main techniques for food preservation were brining, freezing, drying, and smoking. The precursor of the Cajun Boucherie was the slaughter of pigs and cows each autumn by neighbors who would divide the work, then share in the enjoyment of the resulting meat throughout the winter. Part of the meat was frozen in the snow, some was salted and dried, some brined in salted water, and other cuts were smoked in home-fashioned smokehouses. Cod and herring for family use were salted, eels frozen, and herring smoked.
Root vegetables were kept in cold storage in cellars; while corn and beans were dried, to be reconstituted as needed. Green beans were salted, as were cabbage and herbs. Chives and onion tops were used as herbs, and were the primary seasonings in most savory dishes–much the same way onion, celery, and bell pepper are the primary seasonings in Cajun cooking. Berries were made into jam; apples put in cellars for cold storage, just as apples are today; cranberries stored in light brine; and blueberries and apple slices were laid out in a single layer and dried. Eggs were gently layered in oats and put in cellars for cold storage; and butter was formed into blocks and kept in lightly salted water.
So, you can see that the additions of water bath canning and pressure canning added more ways to preserve a bountiful harvest. According to wikipedia:
During the first years of the Napoleonic Wars, the French government offered a hefty cash award of 12,000 francs to any inventor who could devise a cheap and effective method of preserving large amounts of food. The larger armies of the period required increased and regular supplies of quality food. Limited food availability was among the factors limiting military campaigns to the summer and autumn months. In 1809, a French confectioner and brewer, Nicolas Appert, observed that food cooked inside a jar did not spoil unless the seals leaked, and developed a method of sealing food in glass jars. The reason for lack of spoilage was unknown at the time, since it would be another 50 years before Louis Pasteur demonstrated the role of microbes in food spoilage. However, glass containers presented challenges for transportation.
Glass jars were largely replaced in commercial canneries with cylindrical tin or wrought-iron canisters (later shortened to “cans”) following the work of Peter Durand (1810). Cans are cheaper and quicker to make, and much less fragile than glass jars. Glass jars have remained popular for some high-value products and in home canning. Can openers were not invented for another thirty years — at first, soldiers had to cut the cans open with bayonets or smash them open with rocks. The French Army began experimenting with issuing canned foods to its soldiers, but the slow process of canning foods and the even slower development and transport stages prevented the army from shipping large amounts across the French Empire, and the war ended before the process was perfected. Unfortunately for Appert, the factory which he had built with his prize money was razed in 1814 by Allied soldiers invading France.
Following the end of the Napoleonic Wars, the canning process was gradually employed in other European countries and in the US.
Kind of interesting that the French started this, right?
And, of course, came canning this at home. According to eHow, the water bath method is defined as:
The boiling water bath method is simple, requiring a pan with a rack or dishtowels packed in the bottom to create an even heat distribution within the contents of the jars. Dishtowels or a canning rack are also necessary to prevent the jars from bumping into one another and cracking. The jars are packed and covered with a canning lid that uses wax to seal the jars during the heating process. Water is poured over the canning jars, allowing 1 to 2 inches of water to cover them, and the water is brought to a boiling temperature. For acidic fruits and vegetables, a temperature of 180 to 212 degrees F should be reached and maintained for 5 to 85 minutes, depending on the fruit.
And, then you have pressure canning:
Pressure canning methods are used for low acidity foods that cannot have their pH raised above 4.6 without compromising taste. Pressure canning uses a special pot that can be sealed to keep steam in. The lid can be vented and has a gauge to display canning pressure, as pressure is especially important in the preservation of meats and other low-acid foods. Similar to the water bath method, the jars should be placed on a rack or dishtowels to prevent jars from breaking or touching the bottom of the pot. Low acidity foods should be processed at a temperature of 240 to 250 degrees F, or pressure of 10 to 15 lbs. per square inch, easily measurable from the pressure gauge on the lid of the pot. Pressure canning times range from 20 to 100 minutes.
Basically, high acid foods like tomatoes, applesauce, peaches and other fruits can be safely canned in a water bath canner. For most, that is a good place to start as there isn’t any concern about high heat and pressure. Low acid foods, like veggies; corn, peas, potatoes, green beans, and meats all require pressure canning to make certain all nasty things are killed. Using a pressure canner isn’t hard, it just takes practice.
All you really need to do is read the instructions that come with your canner and follow those. Allowing your canner to vent steam at the beginning of each process allows it to get up to pressure faster, and allowing it to cool on its own accord saves you from any possibility of burns or explosions from trying to overcome the internal pressure.
Many pressure canners will have a pressure valve, and an overfill valve on it. The pressure valve is what “pops” up as the canner is getting to the correct amount of pressure, and the overfill valve is the black stopper on the opposite side. If this pops out, the canner was overpressurized. You will need to turn off the heat, let it cool, and start over. I have honestly never had this happen, and I am told this is quite rare.
How do you preserve your garden goodness? What is your favorite technique? Be sure to pin this for later!