Preserving Foods – Freezing Methods
It is probably no news to you that there are many ways to preserve foods. For centuries foods have been preserved by various methods. Freezing, drying, salting, boiling and fermenting are all common methods used to preserve food. The ultimate goal of food preservation is to slow the rate of bacterial growth as well as other chemical reactions so the food will last longer.
Freezing is by far the easiest and one of the best methods to preserve food when on a tight budget.
According to a recent article in Canadian Living, freezing food stops the growth of bacteria completely. Bacteria are essentially what create mold and other spoilage.
If bacteria growth stops completely when freezing food, does that mean that frozen food can stay in the freezer for a very long time? The answer is yes and no.
It all depends on the food itself; it’s chemical properties and various other circumstances such as it’s environment and the overall method of preservation. While bacterial growth is stopped completely when freezing food, enzyme activity within the food only slows down.
Enzymes are proteins that make and create chemical reactions. Enzymes are what initially help certain foods to grow and mature. Once a food hits it’s maturation period, overtime it will start to loose it’s flavor and quality. The reason for this is that the enzyme is still active in the food and since it’s a protein it can’t ever be destroyed.
Enzymes however can be slowed down and even put in an environment where they become inactive or loose their functions. They do not react well in extreme heat, in alcohol, or in acidic and dry conditions. In cold temperatures they slow down.
Have you ever thought about wine? Why does it last so long? It’s because the grapes are fermented with the alcohol, making the enzymes inactive and helping to preserve the grape and keep it from further maturation. The same process goes for a lot of other different foods.
So when it comes to freezing foods, some foods can be simply frozen while other foods will need to have other preparation to help slow down enzyme reactions. Ultimately one does need to realize that food in the freezer will not last forever. It is simply a method of preservation.
Starchy foods such as breads and cakes do not need any prep work, they can simply be frozen and have a preservation rate of about three months. After three months they start to loose their taste and texture. The enzymes still work in the cold, slowly aging the food.
Fresh vegetables and herbs on the other hand will need prep work done before they can simply be put in the freezer. While popular belief is that vegetables can be frozen directly, that only goes for store bought. Fresh grown vegetables will have longer preservation life if they are first boiled. Boling the vegetables disable the enzymes to react, preventing further activity and also destroying living microorganisms. Herbs need to be submerged in water because water crystals will form around the herb protecting it from further chemical activity. Once the herb has been thawed and brought back to normal temperature, as with any other food, chemical reactions and enzyme activity will come back. Vegetables and herbs can last up to 10 months in the freezer.
This brief explanation on freezing food is just one of the many methods of food preservation. Of course there are plenty of other types of foods that can be frozen as well as other methods to preserve.
To find out more about food storage and preparation please plan on attending the Idaho Preparedness Expo on Saturday the 19th of September at Madison High School.