I have had many people ask me why the rules of preserving food are so specific. Our ancestors preserved their gardens as a necessary form of survival while we ‘put away’ food as a hobby or a way to save money. Unfortunately for our ancestors they were not nearly as well informed about the science involved in home food preservation as we are; I assume they lost a great deal of time and food while perfecting the art of canning. We are no longer required to suffer through the trial and error process.
Pressure Canning VS Boiling Water Canning
One of the first questions people ask when learning about home food preservation is, “what is the difference between a pressure canner and a boiling water canner? And how do we know which one to use?” Here is the answer.
The (Jayme Payne) definition of home canning is: Preparing food for long term storage by killing the microorganisms with heat and then using an airtight seal to prevent recontamination. The invention of a specially designed glass jar with a two piece metal lid that allows air to escape and then seals tightly has solved the problem of potential recontamination. The big question now-a-days is to insure that the food spoiling microorganisms (such as mold, yeast, bacteria, etc) are properly removed before the jar is sealed.
Microorganisms that cause food to spoil are affected by a foods’ level of acidity (or pH). In home canning we categorize foods into two groups, high and low acid foods. Each of these groups requires a different processing method.
High-Acid Foods – The ‘Ball Home Preserving’ book defines high-acid foods as “Foods or recipes with a pH of 4.6 or lower”. These foods can be safely processed in a boiling water canner, which heats food to 212° F. High-acid foods include pickles, fruits, jams, jellies, and fruit spreads. Other foods, such as figs and tomatoes, are ALMOST high-acid foods and therefore require the acidity level to be increased prior to processing. This is done by adding vinegar, lemon juice, or citric acid. Recipes that combine high AND low acid ingredients must have a pH of 4.6 or LOWER for the jars to be processed in a boiling water canner. This includes pickles, relishes, salsa, and condiments. If you are not comfortable testing pH levels I recommend only using recipes from a trusted home preserving source.
Low-Acid Foods – Low-acid foods naturally have very low levels of acidity. These foods must be processed in a pressure canner. This group includes vegetables, beans, meats, poultry, and seafood. Recipes that contain high and low acid foods must be treated as a low-acid food; including soups, stews, tomato-vegetable mixtures, tomato-meat mixtures and meat sauces. Foods with a pH greater than 4.6 are considered low-acid foods and must be heated to 240° F in order to kill the bacteria.
Boiling Water Canners (click the picture to purchase NOW)– I don’t actually own a “boiling water CANNER”. What I do have is a very large, heavy duty, stainless steel pot. Any pot can act as a boiling water canner as long as it is at least 3 inches deeper than the height of the jars. This allows enough room for the jars to be covered by at least 1 inch of water while leaving enough space for the water to boil rapidly.
Pressure Canners (Click the picture to purchase now)- A pressure “COOKER” is NOT a pressure “CANNER”. While a pressure canner may be used as a pressure cooker a pressure cooker cannot be used as a pressure canner. A pressure canner is a tall pot with a locking lid and a device that regulates the pressure inside the pot. Many people feel that pressure canners are complicated or dangerous but if they are well taken care of and used properly they will safely preserve food for more years than you will have a desire to use them. The most important thing to do if you own a pressure canner is to have it tested by your local extension agency every year. Pressure canner processing weights are dependent upon your altitude and the accuracy of your pressure canners gauge. Last year the gauge on my canner was deemed accurate at 13lbs, so whenever I process jars (no matter what they contain) I will keep the dial on my gauge at 13. The amount of time a batch is processed for will depend on the size of the jars and their contents.
If you have previously felt intimidated by the idea of using a pressure canner, STOP NOW!! There are so many fun and useful things you can preserve with a pressure canner, don’t miss out just because you haven’t ever done it before. You will be surprised at how easy home food preservation can be!