Food Preservation Blog
To can or to freeze?That's the eternal question many home cooks face at this time of year when summer's bounty stands ready to go into storage.If you want those pretty fruits and vegetables you lovingly plucked from your home garden — or from the table at the local farm market — to reappear all fresh and tasty at midwinter you'll need to decide whether they're headed into freezer bags or mason jars.
Corn can be preserved with equally good results by freezing or canning. Corn may also be dried. Preserve corn as soon after harvesting as possible. The corn will be best if canned or frozen within six hours of being picked. Select tender ears of corn with milky kernels. After husking and removing the silk, trim off the ends of the ears to remove small fibrous kernels. Wash corn before blanching.
What is a vacuum seal? When you fill a jar with food and apply a lid at room temperature, the atmospheric pressure is the same inside the jar as it is outside the jar. When the jar is heated as in water bath or during pressure canning, the air and food inside the jar expand; this forces air out of the jar. As the jar cools and the contents shrink, a partial vacuum forms. The sealing compound found on the underside of the lid prevents air from re-entering the jar so that no microorganisms can enter the jar to recontaminate the food.
Many gardens contain a wide variety of vegetables. Some are grown because they are favorites. Others are grown for the fun of trying something new. Here are some suggestions for preserving some specialty vegetables.
Tomatoes and tomato products need to be acidified for home canning. A common misconception is that tomatoes are a high acid food. With a pH of 4.6 tomatoes are right on the border between being high or low acid. The tomato variety and growing conditions (blight and diseased plants) can easily tip the acidity level to the low acid side of the scale.
Tomatoes are one of the most commonly canned vegetables. Because many canning procedures for tomatoes have been handed down from generation to generation, there are many canning recipes that are inadequate to kill all spoilage microorganisms.
Salt is generally added to canned foods to enhance their flavor. With the exception of fermented pickles and sauerkraut, salt is an optional ingredient. Salt can be omitted for canning tomatoes, vegetables, meats, poultry, and seafood since the amount added does not contribute to the safety of the food. However, in fermented sauerkraut and brined pickles, salt not only provides characteristic flavor but also is vital to safety since it favors the growth of desirable bacteria while inhibiting the growth of others.
Red, green, yellow—even purple and orange. Peppers make a colorful medley. The most common peppers are the mild, sweet, thick fleshed bell pepper; the even milder pimiento pepper; and the hotter chili and jalapeno peppers. Some gardeners include the much hotter serrano, cayenne and habenero among their favorites. Peppers may be frozen, canned, dried, pickled, marinated or made into relishes, jams or jellies.
The ideal texture of a good pickle is its crispness. According to Brian Nummer, Extension Food Safety Specialist at Utah State University, that crispness comes from the vegetable’s natural pectin. Pectin can be described as the cement that holds the cells together.
To preserve the delicate flavor of a summer favorite, can peaches when they are at the ideal stage of ripeness and select a variety that maintains its flavor and shape through the canning process. Many new varieties are available; ask the grower how a specific variety will perform. If you are canning large peaches, you may choose to use wide mouth jars to avoid bruising when placing them in the jars.
What can you do with extra zucchini? You can dry or freeze zucchini, but you can only can zucchini if it has added acidity as in pickled products.
Sometimes directions for pressure canning say to process a food at 10 pounds pressure for a given time. These directions are either very old or written for a weighted gauge pressure canner.
The principle causes of spoilage in home food preservation are microorganisms and enzymes. Because molds, yeasts, and bacteria are found everywhere—in the air and soil, on people and animals, and on many surfaces—proper food preservation methods must be used to prevent them from causing food to spoil. The effects of these microorganisms can range from soft, slimy textures and unpleasant odors to food poisoning that can be deadly.
Follow these suggestions to prevent spoilage of home preserved foods caused by molds, yeasts, bacteria, and enzymes.
Since the late 1980’s extension educators have been teaching that open kettle canning is no longer safe. Gradually, home food preservers are abandoning this practice and moving to processing all canned goods. Some of our educators have found that our young people may not even know about open kettle canning.
Although a jar of olive oil with sprigs of fresh tarragon floating in the center has eye appeal, it is not a safe food preservation method. Storing vegetables or herbs in oil is not recommended because both the herbs and the oil provide conditions that can support the growth of Clostridium botulinum bacteria. The heat stable spores of this bacteria can produce deadly amounts of toxin in environments that are free of oxygen, at room temperature, and low in acid.
Why is it necessary to pressure can certain foods? Some foods naturally have less acid than others. Low acid foods require higher temperatures to kill harmful bacteria. The only way to reach these higher temperatures is to process low acid foods in a pressure canner. High pressures raise the internal temperature of the canner to 240°F at 10 pounds pressure in a weighted gauge canner or 11 pounds pressure in a dial gauge canner. This compares to 212° F in a boiling water bath.
Peaches, strawberry jam, peas, beans, chicken, vegetable soup? Which method of home canning is suitable and safe for each product? The most important choice for a safe product is to choose the processing method that will destroy all harmful bacteria and prevent their growth during storage.
Crisp, tender sugar peas combined with new potatoes make a tasty dish that signals the beginning of a bountiful garden. English or hull peas are equally delicious. With careful processing, peas can be preserved to be enjoyed throughout the year.
One of spring’s favorite vegetables, asparagus, is so delicate that it requires special care.
Rhubarb is the vegetable that is enjoyed as a fruit. By itself it provides a unique tart flavor. Unlimited possibilities exist for combining rhubarb with other foods to create delicious sauces, pies, cakes, cobblers, muffins, and even jams. Most foods prepared with rhubarb can also be frozen.
