Easy orange marmalade

4 lbs oranges*
5.5 cups granulated sugar
5.5 cups brown sugar
juice of 2 lemons
1 tsp vanilla extract

1. Boil oranges, in enough water to allow them to float away from the bottom in pan, for two hours.
2. Remove from the water, wipe off, and allow to cool until they can be safely handled.
3. Cut each orange in half, remove seeds, and squeeze the juice into a saucepan. (This is simply to keep the juice from squirting all over your cutting board! If the flesh is still firm, you can just chop it.)
4. Finely slice the rind and roughly chop the pulp.
5. Add orange solids, sugars, lemon juice and vanilla to the orange juice.
6. Bring to a boil.
7. Run about half the mixture through a blender at this point if you want fewer peel shreds, and return to the saucepan.
8. Bring back to a boil and simmer for 15-20 minutes.
9. The jam is ready to can. Process in a hot water bath for 15 minutes.

* I've tried this recipe with grapefruit and orange, and I suspect that lime would work equally well. To cut the bitterness of the grapefruit, I added a teaspoon of baking soda with the sugar. Another way to decrease the bitterness is to separate the membranes from the citrus fruit before chopping, tie them in cheesecloth (for the pectin) and remove the pouch from the marmalade before canning. I'm looking forward to combining orange and lime for a combo marmalade.