Home Canning: Ensuring High-Quality Canned Foods
Maintaining Color and Flavor in Canned Food
To maintain good natural color and flavor in stored canned food, you must:
- Remove oxygen from food tissues and jars,
- Quickly destroy the food enzymes,
- Obtain high jar vacuums and airtight jar seals.
Follow these guidelines to ensure that your canned
foods retain optimum colors and flavors during
processing and storage:
- Use only high-quality foods which are at the proper maturity and are free of diseases and bruises.
- Use the hot-pack method, especially with acid foods to be processed in boiling water
- Don't unnecessarily expose prepared foods to air. Can them as soon as possible.
- While preparing a canner load of jars, keep peeled, halved, quartered, sliced, or diced apples,
apricots, nectarines, peaches, and pears in a solution of 3 grams (3,000 milligrams) ascorbic acid
to 1 gallon of cold water. This procedure is also useful in maintaining the natural color of
mushrooms and potatoes, and for preventing stem-end discoloration in cherries and grapes. You
can get ascorbic acid in several forms:
Pure powdered form seasonally available among canners' supplies in
supermarkets. One level teaspoon of pure powder weighs about 3 grams. Use 1 teaspoon per
gallon of water as a treatment solution.
Vitamin C tablets economical and available year-round in many stores. Buy
500-milligram tablets; crush and dissolve six tablets per gallon of water as a treatment solution.
Commercially prepared mixes of ascorbic and citric acid seasonally available
among canners' supplies in supermarkets. Sometimes citric acid powder is sold in supermarkets,
but it is less effective in controlling discoloration. If you choose to use these products, follow
the manufacturer's directions.
- Fill hot foods into jars and adjust headspace as specified in recipes.
- Tighten screw bands securely, but if you are especially strong, not as tightly as possible.
- Process and cool jars.
- Store the jars in a relatively cool, dark place, preferably between 50°F and 70°F.
- Can no more food than you will use within a year.
Adapted from the "Complete Guide to Home Canning," Agriculture Information Bulletin No. 539, NIFA-USDA (Revised 2015). Page reviewed February 2, 2017.