Preserving your food at home is a rewarding way to enjoy the fresh quality of ingredients all year round. In this post we are going to explore how to safely extended the quality of your food for many months. Bellow are, the top five mistakes beginners make when preserving food and how to avoid them.
1. Water Bath Canning Low-Acid Foods
One of the worst mistakes a home canner can make is to ignore food acidity levels. Different types of food have different types of acidity and this will influence the type of process to use when canning your food.
High-acid foods have a (pH 4.6 or lower) and low-acid foods are with a (pH above 4.6). High-acid foods can be safely processed in aboiling-water canner, however low-acid foods such as meats, poultry, seafood and most fresh vegetables, require a pressure canner. Read more about food safety on this guide by the FDA for best practices when preparing your ingredientes.
The reason behind this separation is biological: Clostridium botulinum. These heat-resistant spores can survive boiling temperatures. To destroy these spores that produce a deadly toxin that causes botulism, the food must reach 250° F (121° C) during the process and this is the reason why low-acid foods need to be preserved using a pressure canner.
Tip: Always use a pressure canner for vegetables and meats. In this article by the CDC you can learn more about on how to prevent botulism when preparing your food.
2. Using ”Grandma’s” Untested Recipes
As tempting as can be to use old family recipes, you should keep in mind that many were created before food safety was a concept. The ingredients we use today also change since then. For example, some of the modern tomato varieties are less acidic than the ones grown decades ago, this means the process that they go under when preserved also changed.
To ensure safety, a recipe must guarantee a ‘log reduction’. If you are unfamiliar with this concept,the Fda provides for a useful guide on how to ensure that harmful microorganisms like Salmonella or E.coli are reduced to a safe level during preparation.
Good to Remember: Follow verified sources for your recipes. In the National Center for Home Food Preservation (NCHFP) you have verified recipes if you are looking for inspiration. This will ensure that your final product is safe to consume.
3. Ignoring Altitude Adjustments
If you are canning at an altitude above 1.000 feet, you may need to adjust the time or the pressure in your process, altitude will affect the required conditions for a safe result. Always check if you have the right temperature inside the jar during the canning process or it may never reach the point needed to destroy the pathogenic bacteria.- INSERIR TABELA
Practical Tip: Determine the altitude on your area and follow the specific adjustment chart found in tested recipes. Remember that pressure alone does not kill microbes; it is the high temperature that ensure safety.
4. Incorrect Headspace
‘Headspace’ is the name given to the empty space between the food and the lid in one jar. Beginners often miss this mark.
Having the proper headspace is critical. It will allow for a vacuum seal to form as the jars cools down. If the headspace is too small, food may expand and interfere with the sealing surface. If too large, the air may not be completely driven out, preventing a strong seal.
Practical Tip: Use a headspace tool to measure exactly what the recipe calls for – usually 1/2 inch for fruits and 1 to 1 ¼ inches for meats and vegetables in a pressure canner.
5. Reusing Single-Use Lids
Standard canning lids are intended for single use and they have a specialized sealing compound. Once the lid is used, the compound may not provide for a reliable airtight barrier if used again. Reusing lids will increase significantly the risk of contamination and this might cause air and bacteria to leak back into the jar during storage.
Safety Tip: Always use new flat metal lids for every batch. You can safely reuse the metal screw bands as long as they are clean and free of rust.
Final thoughts on Safety
Foodborne pathogens cannot always be seen, tasted or smelled. A jar that looks and smells fresh can still be dangerous if not prepared correctly. Good Practices as keeping your ingredients fresh before canning, following safety guidelines for food storage and using verified recipes will lead to a pantry full of good quality products.
If can find out more about the Four Main Methods of Preservation, in our article : The Home Preservation Journey: A Beginner’s Guide to a Self-Sufficient Pantry. And remember to follow the golden rule of Home Canning, and ”When in doubt, throw it out!”
Frequently Asked Questions (FAQ)
Is food always safe to eat if it looks and smells fine?
Not necessary, as food can make you very sick even when it looks and smells good. This is do to pathogenic bacteria, which cause illness, these are different from spoilage bacteria that make food ”go bad” and produce visible mold or bad odors. As prevention always follow the correct procedures when preparing your canned food.
Does freezing food kill the bacteria present on it?
Freezing does not kill most bacteria, as commonly believed. Instead it causes the microbes to enter a dormant state and stops them from growing, and bacteria can become active again once the food is thawed. But maintaining the correct freezing temperature 0° F (-17.8° C) will allow you store food for many months.
How can I tell if a home-canned jar has become dangerous?
Check your jars for signs of damage such as swelling, leakage, punctures or deep rusting. These are signs the canning process failed. Heat-resistant spores can germinate and produce harmful toxins inside the jar. If any of this signs is noticeable there is probable contamination inside the jar.