Science behind food preservation methods
Why has food preservation times, pressures and methods changed?
Your family has preserved food in jars for years, so why would you need to go to a food preservation class? While many food preservation methods that have been used in the past are still used today, some have been updated to follow the latest food preservation science.
When preserving food, first you need to decide what you are preserving, which will help you decide what method will be used. So let’s talk about methods of food preservation.
Dehydrating is one of the first forms of food preservation. This method removes moisture from food. Removing moisture from the product reduces the ability of bacterial growth by taking away the element it needs to grow.
Water bath canning is used when putting your high acid foods, such as fruits and tomatoes, in a jar. One thing science has dictated is that we need to add acid to tomatoes when canning them. Jams and Jellies can be safely water bathed for safe preservation. Because of science, the length of time produce is in the water bath canner has also increased to ensure that the heat has reached the center of the jar to kill any bacteria or enzymes in the product.
Pressure canning is another preservation process that requires putting product in a jar. However, these items are considered low acid and need to be processed using a pressure canner. Science has changed the length of time and the amount of pressure used when canning in a pressure canner.
Pickling is a method of preservation that has a high concentration of acid. Pickled products are saturated with acid to smother out most bacteria. Heat treating these products is also important to kill any remaining bacteria in the jar.
Freezing food is a quick and easy method of food preservation. Many things can be frozen which slows growth of enzymes but does not eliminate them. When foods are removed from the freezer microorganisms begin to grow once they reach a thawed state.
Fermentation is a method of preservation the can add a little bit of healthy nutrition to a diet. It is an old way of food preservation that adds flavor after the fermenting process is done. Fermenting is a process done in a warm environment using salts, sugars or grains creating a brine, which covers the produce. Time is another important factor when fermenting.
Michigan State University recommends using only science based methods to preserve foods that are intended for later use. For more information on methods of food preservation refer to USDA national food preservation website, So Easy to Preserve or the All New Ball Blue Book of Canning and Preserving.