This is a sweet marmalade, with just a hint of bitterness. It is not strongly bitter like Seville orange marmalades are, but it has just a touch of bitterness which i think sets off the sweetness nicely. I adapted this recipe from Rachel Saunders' method for making marmalades. The pectin in this recipe comes from the fruits themselves, which are blanched once to remove some of the bitterness, and then soaked to leach the pectin out of the rinds. You will need to use the cold plate test to determine when the marmalade is finished cooking - I have included instructions on how to do this below. You could also use Valencia oranges in this recipe, if you wish. The sugar is added after the liquid has been reduced for two reasons: The peel must be cooked until it is thoroughly soft, and if the sugar is added at the beginning of the cooking it will have a hardening effect on the peel. Also, adding the sugar after the liquid has been reduced produces a fresher-tasting marmalade, because the sugar does not cook for a long time and begin to caramelize. However, if you prefer a darker, more caramelized marmalade, and don't mind the rind being a bit chewy, go ahead and add the sugar at the beginning of the cooking process (i.e. the "marmalade" cooking process, not the "juice" cooking process). This is an old fashioned recipe which takes at least 2 days, due to the soaking. It is not quick, but it is delicious.