If you live at an altitude of 1,000 feet or more, you have to add to these processing times in canning directions, as follows:

Altitude Increase in processing time if the time called for is—
20 minutes or less More than 20 minutes
1,000 feet 1 minute 2 minutes.
2,000 feet 2 minutes 4 minutes.
3,000 feet 3 minutes 6 minutes.
4,000 feet 4 minutes 8 minutes.
5,000 feet 5 minutes 10 minutes.
6,000 feet 6 minutes 12 minutes.
7,000 feet 7 minutes 14 minutes.
8,000 feet 8 minutes 16 minutes.
9,000 feet 9 minutes 18 minutes.
10,000 feet 10 minutes 20 minutes.

To Figure Yield of Canned Fruit From Fresh

The number of quarts of canned food you can get from a given quantity of fresh fruit depends upon the quality, variety, maturity, and size of the fruit, whether it is whole, in halves, or in slices, and whether it is packed raw or hot.

Generally, the following amounts of fresh fruit or tomatoes (as purchased or picked) make 1 quart of canned food:

Pounds
Apples 2½ to 3
Berries, except strawberries 1½ to 3 (1 to 2 quart boxes)
Cherries (canned unpitted) 2 to 2½
Peaches 2 to 3
Pears 2 to 3
Plums 1½ to 2½
Tomatoes 2½ to 3½

In 1 pound there are about 4 medium apples, peaches, or tomatoes; 3 medium pears; 12 medium plums.

Directions for Fruits, Tomatoes, Pickled Vegetables

Apples

Pare and core apples; cut in pieces. To keep fruit from darkening, drop pieces into water containing 2 tablespoons each of salt and vinegar per gallon. Drain, then boil 5 minutes in thin sirup or water.