Scrub the outsides of the oranges clean and pat dry.
Slice the oranges and lemon in half.
Juice the citrus into a large measuring cup, with a sieve set over top, and set the juice aside.
Place the pips and pulp into a jam bag or into a large double square of cheesecloth. Keep this open, as you can add more orange pith if you'd like. [The pits and pith are the source of pectin in this recipe. So, don't skip this step!]
With a knife or a grapefruit spoon, scrape the remaining pulp out of the oranges and place in bag or cheesecloth.
Slice each of the orange half-rinds into quarters. [The lemon rinds may either be incorporated into the marmalade or discarded.]
With a knife, remove as much of the white pith as desired. [I usually remove enough so that the pith looks "freckled."]
Place as much of the pith as you'd like into the muslin bag or cheesecloth.
Tie the jam bag or cheesecloth with kitchen twine and set aside.
Slice the rinds into thin strips.
In a large pot [but not a copper jam pan], combine the orange juice, the lemon juice, the water, and the tied-off bag of pips, pulp, and pith.
Cover and set aside in a cool place for at least 2 hours, preferably overnight. You've done all of the tedious work! Time to take a break!
In a large, heavy bottomed pot or in a copper jam pan, over medium heat, bring the ingredients of the overnight-pot to a boil. Then, simmer over medium-low heat for 45 minutes to an hour, until the sliced rinds are squishable but not sloppy.
Turn off the heat momentarily.
Remove the bag of pips and piths from the liquid and strain by using one of the two options. OPTION 1) Using two pairs of tongs, hold one pair at the top to secure the bag and use the other pair of tongs to squeeze all of the liquid out of the bag and into the pot. OPTION 2) Set the bag aside in a bowl until it is cool enough to squeeze the bag by hand into the pot.
Add the sugar to the pot on the stove.
If you prefer to cook off the alcohol to make the marmalade friendly, add it now. [I add mine after bringing the jam to the setting point.]
Stir the marmalade mixture over low heat until all of the sugar has dissolved.
Fit the pan with a candy thermometer and bring the marmalade to a low boil over medium-low heat.
Cook, stirring occasionally, until the jam reaches 104.5 Celsius [220 Farenheit] on the candy thermometer.
Remove the pot from the heat and use a spoon to skim the foam from the pan, discarding the foam.
If desired, add the Cognac or Whisky and stir to incorporate.
If you are not going to seal the jars for long-term storage, allow the jam to cool a bit more before ladling into containers, so that you can stir a bit, making sure the rinds don't settle to the bottom. Then, ladle into jars and refrigerate.
If you are properly canning the marmalade, immediately ladle the hot jam into warm, sterilized jars, careful to disseminate the peels evenly from jar to jar, leaving 1/4-inch headspace.
Seal the jars with lids and rings and process in a boiling water bath for 10 minutes before removing from the bath and allowing to cool completely.