Mimi brought over 2 1/2 pounds of blood oranges, or 13 3 ounce fruits. She wondered what sort of marmalade these would make – and so did I. In order to really taste this rather subtle citrus, no flavoring, such as vanilla or spice, was added. Start by soaking and scrubbing the fruit, then cut 1/4″ from each end and halve. Cut out a little triangle of core and put in the cheesecloth lined bowl for the pectin bag, scraping out any seeds at the same time. Slice each half thinly, and measure. 2 1/2 pounds yielded 8 cups of sliced fruit. Put in a large pot, add an equal amount of water and the pectin bag, and boil for 30 minutes, then cover and take off the heat. At this point, let the mixture sit about 8 hours, usually overnight, or refrigerate for later use.
The golden rule for marmalade and preserves is to cook no more than 6 cups per batch. Since this yielded 8 cups of cooked mixture, I split it into 2 batches of 4 cups each. Bring the fruit mix to a boil, then add an equal amount of sugar, which in this case was 4 cups. Add 2 tbsp of lemon or lime juice. Keep the mixture at a boil. Bring the canner to a boil and have your jars ready. This reaches the gel stage in about 30 minutes, but can take longer, depending on your stove. Ladle into jars leaving 1/4″ head space, and process for 10 minutes. This yielded 18 4 ounce jars.