Witness my last try at using Bergamont oranges for this season. We have more marmalade than we can use already, but my buying frenzy of the Bergamonts made this recipe necessary. The blood orange version was so good, it's just hard to beat, but if you never tasted a Bergamont marmalade, this one would be a good introduction for the purist.
6 medium navel oranges
5 large Bergamont oranges
Each of my marmalades follow the same instructions: peel rinds from the fruit (scoring the exterior into vertical 4ths with a paring knife works best for me), boil them, scrape off pith, then slice as thin as possible. My knife skills are improving by leaps and bounds, thanks in part to making marmalade.
These photos illustrate an important concept for home canning. The 1st shows the preserve boiling away, but after stirring, the 2nd illustrates that the bubbles backed down, indicating that the fruit has not yet reached a setting point (the ability to firm up without added pectin). There is so much natural pectin in citrus fruit that it doesn't need pectin if it is brought to a "rolling boil" that will not stir down, as seen in the 3rd photo.
Again, as with all the other marmalade recipes, combine an equal portion of sugar to the fruit pulp, juice and rinds that you have measured. In this particular recipe, I only used 2 navel orange rinds in the mix with all the Bergamont orange rinds. I used all the pulp and juice from each kind of orange, but I would consider just juicing the oranges and eliminating the pulp for a different version. For the very last jar, I added 1/2t of almond extract just to see if I liked the taste.