Canning cranberry sauce, rather than freezing whole berries, is an economical and space-saving method of preserving cranberries for year-round use. Buying cranberries from growers in bulk or on sale in the grocery store also saves money. Proper canning and processing methods are necessary to prevent spoilage and help the cranberry sauce set. Canning cranberry sauce requires the use of a boiling water bath canner. It also is important to properly prepare the sauce, leave the correct amount of headspace in the jar, correctly pack the jars and ensure correct processing times.
Before making and canning cranberry sauce, it is essential to select the freshest, ripest cranberries available. Fresh cranberries are sold in pre-packaged plastic bags in the produce section of most grocery stores. A person should choose bags that contain the largest amount of dark red, brightly colored cranberries. The peak season runs from October to December and, the earlier they are purchased, the fresher they will be. The purchased cranberries should be rinsed, stemmed and sorted, and any that are discolored, soft or shriveled should be discarded.
The boiling water bath canner should be preheated before the cranberry sauce is prepared. One should check to be sure the bath canner is large enough to accommodate the size of the jars and tall enough to allow a minimum 4-inch (10 cm) space above the top of the jars. Another large pot of hot water is necessary to keep the jars and lids hot while the cranberry sauce is being prepared. The hot cranberry sauce must go into hot jars and be placed immediately in the boiling water bath. Without proper preparation, the cranberry sauce will not set, resulting in a liquidy, runny sauce, regardless of whether one is canning cranberry sauce in whole or jellied form.
One should not allow the cranberry sauce to cool and set prior to canning. For whole cranberry sauce, a ratio of 1 part water, 1 part sugar and 2 parts whole cranberries is recommended. For best results, one should allow the sugar and water to boil for five minutes before adding the cranberries. They should continue boiling, undisturbed, just until the skins pop. Cooking the cranberries longer will result in a bitter sauce.
If a person is making jellied cranberry sauce, then the berries should be boiled in the water, just until they pop, and then pressed through a sieve along with the cooking water. After the sugar is added, the sauce must be boiled until it nearly reaches jellying point — approximately 8° Fahrenheit (13.3° Celsius) above local boiling point or when the mixture slides off a metal spoon in sheets. The hot jars should immediately be filled with the whole or jellied cranberry sauce, leaving a 0.25-inch (0.6 cm) headspace. The lids should be tightened and the jars immediately immersed in the boiling water, ensuring the jars are covered by 2 inches (5 cm) of water. The jars must process in the boiling water for 10 minutes once the water returns to a rapid boil. After removing the jars from the canner, they should be allowed to sit undisturbed for at least 24 hours to help ensure a proper set.