How to do Pressure Canning

For many who love the taste of fresh fruits and vegetables from the summer bounty, home canning is an economical way of preserving that taste. While home canning was practiced long ago out of necessity, it is now making a comeback with today’s thrifty, health conscious consumers.

The hot water bath method is perfect for foods with high acid content, like fruits and tomatoes. However, if you want to venture out into a wider range of foods including most vegetables, meats, fish and poultry the pressure canning method is the only safe and suitable option.

Myths About Pressure Canners

Many home canners have shied away from pressure canners due to myths about their safety. There are stories about explosions and glass jars cracking due to the high pressure. Misuse of an older style pressure canner may have caused problems in the past, but with advances in design and safety features , when properly used, modern pressure canners are as safe as any other kitchen utensil.

Why Use a Pressure Canner?

High acid fruits and vegetables include apples, grapes, pears,cherries and tomatoes. Fruit jams, jellies, sauces and tomatoes can be safely canned using the hot water bath method. Vegetables like greens, squash, corn, beans and carrots are low acid and need to be processed at higher temperatures to destroy bacteria. The bacterium that causes botulism, Clostridium Botulinum is commonly found in vegetables and meat. The bacteria grow and produce dangerous and deadly toxins. The only safe way to process these low acid foods is in a pressure canner where the temperature can reach 240 ° F and safely destroy the bacteria.

Pressure Canners Explained

Modern pressure canners are usually made of lightweight stainless steel or aluminum. They are fitted with a twist on lid and a rack or basket to hold the jars. The lid has a steam vent, a dial or weighted gauge to indicate the pressure and a safety fuse or overpressure plug to regulate excess pressure. Pressure canners can hold one layer of quart jars or two layers of pint or smaller sized jars.

In a pressure canner, the jars do not need to be covered with water. When the lid is fastened, the steam in the canner pushes the air out, leaving only steam and boiling water. The jars will reach a temperature of 240°F, hotter than boiling water. The heat is evenly distributed to thoroughly cook the contents of the jars.

General Instructions

Pressure canners come with different features so it is best to follow the manufacturer’s instructions. Here are some general rules that should work for most models.

1. With the rack in place, put 2 -3 inches of hot water into the canner.

2. Place the filled jars into the canner and secure the lid.

3. Leave the weighted gauge off. Turn the heat high until the water starts to boil and steam starts to come out in a steady stream. Let the steam flow for about 10 minutes.

4. Put the weight on and allow 3 – 5 minutes for the canner to pressurize.

5. Start timing the process when the canner has reached the desired pressure. If there is no dial gauge, time the jiggle of the pressure gauge to several times per minute.

6. At the end of processing, turn off the heat and allow the canner to cool down until the pressure is vented. The pressure dial should read “0” or the weighted gauge releases no steam when touched. Do not try to speed up cooling or force open the lid as this could lead to problems.

7. Lift the weighted gauge, unfasten the lid and remove it carefully to avoid steam burns.

8. Remove the jars with a jar lifter and place them on a towel or cooling rack. Do not set the jars on a cold surface or in a drafty area.

For further information on canning and food safety, call the USDA or your local state extension office.