Eatwell Farm CSA member Nancy sent us this recipe along with some photos of the marmalade making process.
You'll need 6 Seville oranges, top and bottom trimmed. Vertically cut in half, then ¼ vertically from there. Trim interior seeds and set aside. Then cut flesh & rind into small even pieces, about ¼” thick. Put seeds into a muslin cloth “sack”. There's good pectin in seeds.
Take 1 navel orange and cut it in the same manner, removing interior white pith but no seeds to worry about.
Soak all the cut citrus and the seed pouch in an a large non-aluminum pot (I used cast enamel) and cover with 3 C water. Let sit overnight.
Bring to a boil and cook, uncovered for 40 minutes, stirring occasionally. Should be at a “perky simmer”. Not a hard boil but definitely moving. Let stand 4 hours.
Then add 4 C sugar and bring to a boil, stirring constantly (or thereabouts). Boil, stirring constantly until the mixture sheets off the spoon or hits 220 on a candy thermometer.
Turn off the heat and add ½ C fresh lemon juice. (The orange color will intensify and it really pops the flavor. Quite amazing, actually.)
Pour into 7 ½ pt jars.
(Adapted from “The Art Lover’s Cookbook, a Feast for the Eye” Published by the Fine Arts Museum of SF, 1998. Get a copy if you can, it is a beautiful book with some interesting recipes!)