Recipe: How to Can Sweet Potatoes / Yams

They are only safe to can in cubes. Never mash any vegetables when canning.

POTATOES, SWEET - PIECES OR WHOLE
It is not recommended to dry pack sweet potatoes.

Quantity:
An average of 17-1/2 pounds is needed per canner load of 7 quarts; an average of 11 pounds is needed per canner load of 9 pints. A bushel weighs 50 pounds and yields 17 to 25 quarts - an average of 2- 1/2 pounds per quart.

Quality:
Choose small to medium-sized potatoes. They should be mature and not too fibrous. Can within 1 to 2 months after harvest.

Please read Using Pressure Canners before beginning. If this is your first time canning, it is recommended that you read Principles of Home Canning.

Procedure:
Wash potatoes and boil or steam until partially soft (15 to 20 minutes). Remove skins. Cut medium potatoes, if needed, so that pieces are uniform in size. Caution: Do not mash or puree pieces. Fill jars, leaving 1-inch headspace. Add 1 teaspoon salt per quart to the jar, if desired. Cover with your choice of fresh boiling water or syrup, leaving 1-inch headspace.

Process pints 65 min. quarts 90 min. in a pressure canner. Use 10 lb. weighted gauge, 11 lb. dial gauge canner, unless you have to adjust for high altitude.

Taken from USDA guidelines.