Finely chop the kumquats and oranges and combine together in a bowl. Using a cup, measure them into a large saucepan. Add 3 cups of water per each cup of fruit. Let stand in a cool place for 12 hours, or overnight.
Bring the fruit mixture to the boil, reduce heat and simmer until the rind is very tender. Remove from heat and measure cooked fruit. Add one mug of sugar to the pan for every mug of the fruit mixture. Mix in the lemon juice, about 3 tablespoons.
Return the fruit to the pan and bring to the boil once again. Boil, stirring occasionally, until the gel stage is reached (the temperature of the marmalade should be about 105 degrees C when checked with a kitchen thermometer). Remove from heat and skim foam from the surface.
Transfer the mixture to sterile jars, leaving a bit of headspace, and seal immediately. Process any unsealed jars in a water bath. Refrigerate after seal has been broken.
Beautiful sparkling marmalade just like from the shop. This recipe has 4 stars only for confusion because it made me nervous while making it. You could however go to the trouble to remove the peel from the quartered oranges, scrape off more of the white part, and then slice the peel with a knife, if you want to remove any bitter taste, but its good as is. Dont bother rechopping kumquats (just slice them on a mandolin). I wonder why it says to add water and soak overnighta step not called for in other recipes. I decided to add a packet of regular pectin as insurance on warning of another reviewer. - 29 Sep 2008
Everyone loved this marmalade. My mother-in-law loved it so much she asked for the recipe. I only let it soak for 2 hours. Maybe that's why mine came out a little liquidy. And I used a food processor to chop up the fruit. Made it so much easier and less chuckier. - 29 Sep 2008