Cherry Marmalade

From the Ball Blue Book 100th Anniversary Edition 1909-2009

Yield: about 4 half pints

1 quart pitted sweet cherries (4 c.)
2/3 c. chopped and seeded orange (1-2 oranges)
3 1/2 c. sugar
1/4 c. lemon juice

Combine cherries, orange, sugar and lemon juice in a large sauce pot, stirring until sugar dissolves. Bring to a boil over high heat, stirring constantly (about 30 minutes). Cook rapidly almost to gelling point. Remove from heat. Skim foam if necessary. Ladle hot marmalade into hot jars, leaving 1/4 inch head space. Screw on lid and ring. Process in boiling water canner for 15 minutes.