It is believed that, the practice of pickling foods started around 2030 B.C., in Mesopotamia. This tradition has been carried forward throughout the centuries. Even today, homemade pickles are preferred, though ready-made ones that are easily available in the market.
When it comes to homemade pickles, most of us tend to avoid canning, as it is considered as a complicated task. In fact, canning is not difficult, if you know the right method. Canning increases the shelf life of pickles, by preventing entry and proliferation of microbes.
Methods of Canning Pickles
The origin of the canning process is associated with the efforts of humans, to preserve and store food materials for use during adverse conditions. Although various methods were practiced in different regions, there was no single method that enjoyed universal acceptance.
The history of the canning process can be traced back to the initial stages of Napoleonic Wars (1803 to 1815), when the French Government announced a reward for those, who come up with the best method to preserve food materials for a long time. The government had to store large amounts of food material for the army.
This led to the invention of the canning method by a French confectioner and brewer, Nicolas Appert. He was aware that heating food in sealed glass jars increases their shelf life. Later, this method became more advanced with introduction of special canning equipment and machinery, which were designed separately for both commercial and household purposes.
The most common methods of canning pickles at home are the boiling water bath method and the pressure canner method. These methods aim to destroy microorganisms that can spoil the food items. These two methods differ in the type of utensils used for heating and the required temperature level.
Thus, the process of canning helps to preserve pickles for a long time. Above all, it is safe to consume canned pickles than those which are not canned.
Foods with a high acid content can be canned safely by the boiling water bath method of canning. This method involves cooking of the food material at a temperature of 212°F. High acid foods include tomatoes and most of the fruits.
Food items, like carrots, corn, peas, fresh vegetables, meats, poultry, and seafood; have a low acid content, and should be canned by the pressure canner method, which allows cooking at a temperature of 240°F. In this method, the steam trapped while cooking, allows the high temperature to reach the food material.
Such a high temperature is necessary for preservation of low acid foods. When compared to the boiling water bath method, the pressure canner method is slightly complicated and expensive.
Boiling Water Bath Method
Equipment required for the boiling water bath method includes canning jars - which are specially made for the purpose of canning, a large covered water bath canner (with a capacity to hold and immerse the pickle jars with 1 to 2 inches of water covering the top of the lids).
Other equipment includes - a wire basket or rack to fit inside the canner and hold the jars, a jar lifter to take out the processed pickle jars, a wide mouth canning funnel to fill the contents in the jar, and a non-metallic spatula.
Choose wide-mouthed jars without any scratches and breaks. It is always better to use jars that are specially made for canning and preserving pickles. It is not advisable to use bottles of store-bought products, like mayonnaise and jams, as they are not tempered enough to serve the purpose of canning.
The first and foremost thing to do is to sterilize the pickle jars along with the lids, using hot, soapy water. Rinse and air dry the canning jars and lids. Now prepare the pickle of your choice and fill it in the jars, which are already sterilized. Use a wide-mouthed funnel for filling pickles in jars.
Use a non-metallic spatula to run through the contents of the jar in order to release air bubbles trapped in it. Make sure that the content is one inch below the level of the rim. Wipe the jars with a clean cloth, and close the lids. Don't make the lids too tight. Pour some water to the canner, and place the rack that holds the canning jars.
Add more water so that the water level is one to two inches above the jars. Bring the water to a rolling boil, cover the canner tightly, simmer the heat and start the timer. Most recipes provide the timespan for boiling; and for pickles, it is around five to ten minutes.
Once the jars are cool, you have to check the vacuum seal. It can be done by lightly tapping the lid with a spoon. If it is a good seal, you can hear a bell tone instead of a 'clunk'. Make sure by pressing the top of the lid. Good seals do not move down when you press with your fingers.
Pressure Canner Method
Pressure canning is considered a safe method for preserving low acid food items, like vegetables, meats, poultry, and seafood. A special pressure cooker is used for the purpose of canning pickles. Pressure processing is necessary to kill a microorganism, called Clostridium botulinum, which is destroyed by heating food items at a temperature of 240°F.
Though most microbes are killed at boiling temperature, spores of Clostridium botulinum can withstand these temperatures, and continue to grow in the food. As they grow, the spores release botulinum toxins, which can be detrimental for the health of those who eat the food. Hence, it is highly necessary to use the pressure canner method for low acidic foods.
Once you fill the canning jars with pickles, keep them in the special pressure cooker meant for canning. Put two to three inches of hot water in the cooker. The amount of water to be added should be as the per the instructions of the manufacturer. Unlike the boiling water bath method, in this process you don't have to immerse the jars in water.
Allow the water to boil on a high heat setting, with the lid closed and the vent open. As the water boils for ten minutes, the steam inside pushes the air out, and the cooker is filled with steam and boiling water. The temperature inside the cooker will be around 240°F, at that time. Now close the vent, and check the pressure gauge.
As the gauge shows the desired pressure, simmer the heat and cook for around 10 to 15 minutes (time varies with the size of jars and the food item). Turn off the heat, allow the cooker to cool, and the pressure to vent.
Once the cooker is open, take out the canning jars. Let them cool for a day, before storing. To ensure best results, follow the instructions of the manufacturer, while using this special pressure cooker.
Pickles, which are not properly canned, may become a breeding ground for disease-causing microbes. These microbes can cause diseases, like botulism and other types of food poisoning. Therefore, it is very important to understand the process of canning pickles, if you are a person, who likes to prepare homemade pickles.