By Susan Hansen, Extension Educator, Colfax County
Judging by the questions I’ve been receiving lately, people are busy canning and freezing. Based on these questions, here are some hints for better canning and freezing of food.
Use good quality foods when canning or freezing. The quality will not improve. If you can or freeze overripe pears, your end result is overripe pears. If your tomatoes are spoiled when you can them, you’ll still have spoiled tomatoes.
Open-kettle canning is not recommended. This method of canning greatly increases the risk of foodborne illness, particularly botulism. You may say to this, “I’ve been open-kettle canning for years and I’ve never gotten sick.” My response is that you’ve been very lucky. With botulism, sometimes you only get one chance.
The recommended methods of canning are boiling water bath and pressure canning. High acid foods such as fruits, pickles and jellies can be safely canned in a boiling water bath. Low-acid foods such as vegetables and meats need to be pressure canned. Pressure canners reach 240E F compared to boiling water bath which reaches 212E F.
Other methods not recommended are canning in the oven, microwave, crockpot, dishwashers or sun. I have had questions regarding some of these methods.
Use only jars that have been approved for canning. Jars that contained such things as peanut butter or mayonnaise are not recommended for canning for two reasons. One, the glass may or may not withstand the heat from the home canner. Second, jars that knives have repeatedly come in contact with have a greater tendency of breakage. Think about it. Each time a knife or spoon hits the glass while getting in the mayonnaise jar actually weakens the jar, sometimes causing a hairline crack.
When canning tomatoes, add bottled lemon juice to increase the acidity of the tomatoes to help ensure a safely canned tomato product. The varieties of tomatoes have changed over the years with many being less acidic. The ratio is 1 tablespoon of bottled lemon juice per pint of tomatoes.
Properly canned food stored in a cool, dry place will retain optimum eating quality for a year. After that, the product may become mushy and the nutritional benefits begin to decrease.
All jams, jellies, pickles, relishes and preserves need to be processed in a boiling water bath unless they will be stored in the refrigerator. Sealing jams and jellies with paraffin is not recommended.
Most vegetables need to be blanched before freezing. Blanching is needed to stop the enzyme growth to reduce the deterioration of the food.
The variety of cucumber can make a difference with making pickles. Look for pickling cucumbers rather than slicing cucumbers. A slicing cucumber will usually become very soft during the pickling process. Remember to use unwaxed cucumbers when making pickles. The brine cannot penetrate wax.
Color changes occur on some foods in certain situations. Garlic can turn green in pickles because of the reaction between the acid in the vinegar and the color pigment in the garlic. Using overmature dill can cause liquid in dill pickles to turn pink. Beets may turn black if there is a high iron content in the water. Old beets may turn white during the canning process. Corn turns brown during processing because of the carmelization of the sugar in corn. If properly canned, all of the above are safe to eat.