Jar Canning and Preservation 101
Food preservation has a long and varied history, including drying, smoking, and fermenting. Canning or jarring foods has also been popular for a long time, though early methods involved suspending foods in vinegar and alcohol, which did not always produce reliable and safe results. Nicolas Appert was a French chef in the 1800s who is credited with the discovery of the packing, heating, and sealing techniques that are still in use today for canning foods. When John L. Mason invented his reusable jars with screw-on lids in 1858, canning became a popular activity in the United States.
Mechanics of Canning
Canning typically involves filling clean glass jars with prepared foods, applying a flat lid and ring to each jar, and submerging the filled jars in boiling water for the correct length of time based on the contents of the jars. After removing the glass jars from the water, the air inside cools and contracts, sucking the lid down to form an airtight seal. Foods high in acidity that are preserved following these steps should keep safely for at least one year.
- Home canning waned when full service grocery stores began offering processed foods in cans.
- Canning became popular once again in the past few years when consumers wanted to save money and avoid processed foods.
Home canning requires specific supplies, including a wide-mouth funnel, measuring spoons and cups, and a jar lifter. A jar lifter enables you to remove the glass jars from the hot water bath without burning your hands.
- To cook preserves prior to canning, invest in a large non-reactive Dutch oven.
- Use a deep stockpot and a rack for the hot water bath.
The Canning Process
The canning process involves several steps, which are not overly difficult. It is important to follow the steps carefully, however. Use a reputable source for all canning recipes, and follow them to the letter.
- Examine the jars, lids, and rings to ensure that they are in good shape. Wash these items.
- Fill a small saucepan with water and bring it to a boil. Place the jar lids into the simmering water.
- Fill the stockpot with water and heat it. Place the jars inside to sterilize them.
- Prepare the produce while the water heats. Once the produce is ready, remove each jar from the stockpot and fill it. Follow the recipe to ensure that you're leaving the proper amount of head space.
- Wipe each jar rim with a damp paper towel, apply a lid, and screw on the ring firmly.
- Place the filled jars on the rack in the stockpot. Return the water to a boil and start timing the process according to the recipe.
- Remove the jars from the water bath promptly when the time elapses. Place them onto a towel to cool.
- Check the seals after the jars cool. The centers of the lids should become concave; if you push on them, they shouldn't pop up. Remove the bands and double-check all of the lids to ensure that they sealed completely.
- Store the jars in a cool, dark location for up to one year.
- If you have jars that did not seal, refrigerate them and use them first.
Jars may not seal for several reasons. If you have problems with sealing, you may need to make a few adjustments to your process.
- Always ensure that the jar rims are clean and free of debris.
- Boil the lids in water for the length of time recommended by the jar manufacturer.
- Make sure the food is sufficiently hot before packing it into the jars.
- If the food level seems to go down in the jars, this is normal. As long as the jars seal effectively, the canned food should be safe. Try to remove all air bubbles from the food when packing it to prevent this from occurring.
- 26 Canning Ideas and Recipes for the Homestead: Explore recipes for canning fruits and vegetables here.
- How Canning Preserves Foods: Canning removes oxygen and destroys enzymes, which helps prevent growth of bacteria in foods packed in jars.
- Let's Preserve: Basics of Home Canning: Always follow canning procedures carefully to ensure that foods will be safe to eat.
- Safety First When Canning: Canning processes have been used for many years to preserve foods, and it's important not to take shortcuts when canning.
- Home Canning Basics: The water content in fresh fruits and vegetables makes them perishable, but canning helps prevent the growth of bacteria and mold.
- Home Canning in the 21st Century: Home canning is an exact science that can prevent microorganisms from developing in the preserved foods.
- Canning Controversies: No to Home Canning Dairy Products: Home canning of dairy products is unsafe due to the risk of contamination with dangerous bacteria.
- Summer Home Canning Tips: Botulism is a risk with foods that have been improperly canned, and botulism can be serious enough to be fatal.
- Safe and Successful Home Canning: Always use the freshest and highest-quality fruits and vegetables when canning to ensure the best and safest results.
- Pressure Canning (PDF): Pressure canning is the process required for canning low-acid foods to ensure safe results.
- Ten Rules for Safe Canning: Safety rules for canning include using jars and lids that are in good condition and discarding jar rings with rust or jars with chips and cracks.
- General Canning Procedures: When filling jars, remove air bubbles before sealing them or the seals may fail.
- Safe Preserving: Lots of Tomatoes to Can: Tomatoes are acidic enough to can in a water bath.
- Principles of Home Canning (PDF): Processing the sealed jars for the correct length of time is an important part of the canning process.
- Preserving What You Produce (PDF): Once the canning process removes oxygen and destroys enzymes, your fresh foods can be safely enjoyed later.
- Home Canning Questions and Answers (PDF): Sometimes jars can break during the canning process for various reasons.
- Home Canning for Beginners: Always use the correct equipment when canning to make sure that you get safe results from your efforts.
- Canning Vegetables: Those living at high altitudes will need to follow high-altitude instructions for canning.
- Home Canning Vegetables (PDF): Always choose the best vegetables and fruits to can to ensure that the produce doesn't have visible signs of spoilage.
- Let's Preserve: Food Canning Basics: Wash fresh fruits and vegetables carefully immediately before processing them for canning.
- Home Canning (PDF): A pressure canner is necessary for canning meat, fish, and poultry.
- Thickeners for Home Canning: Always follow ingredient lists carefully when using a thickener during the home canning process.