Orange-Grapefruit Marmalade

Directions

1. 1
   Remove peels from fruit and scrape off excess pith. Cut peels into fine strips.
2. 2
   In saucepan, combine peels, baking soda and 1 1/2 cups water. Bring to boiling, cover and simmer 20 minutes.
3. 3
   Meanwhile, remove white membrane from fruit and section, working over bowl to catch juices. Discard seeds.
4. 4
   In 8-10 quart Dutch oven, combine sections, juice and undrained peel. Cover and simmer 10 minutes.
5. 5
   Measure 3 cups cooked fruit mixture; add sugar and mix well.
6. 6
   Bring to full rolling boil and boil, uncovered, 1 minute.
7. 7
   Remove from heat, stir in liquid pectin and skim off foam with metal spoon. Stir and skim for 10 minutes.
8. 8
   Pour into hot, sterilized jars and seal.