For the mandarin/lemon puree*
Start by making the puree. Thinly slice mandarins and lemons.
Measure out 1 ½ cups of mandarins, ½ cup sliced lemons. Add to a medium sauce pan with four cups water.
Cook for 20 minutes or until tender. Allow to cool completely.
Pour into blender. Pulse and puree until small pieces are still visible, not too long as you want to see some of the pieces.
Measure exactly 4 cups puree, freeze remaining for another use.
For the marmalade
Juice lemons and mandarins - measure exactly one cup of each.
Combine all ingredients and cook for 20 minutes at low/medium boil until mixture reaches 221 degrees on candy thermometer.
Stir often to keep from sticking, especially at the end of the cooking.
Ladle into sterile jars. Wipe jar rims and add lids and screw-on rings.
Process in a hot water bath for 10 minutes to seal.
Makes five 8 ounce jars of marmalade.