Clean and separate the hen, cutting out the backbone, wings, wing tips, feet, neck and head. In a large bowl, wash and soak the parts in cold water to remove any blood water. Include any extra bones/parts being used at this stage as well.
Tie the spices into a cheesecloth or spice pouch (I used a tea infuser). In a small bowl, bloom the spices in a splash of high-proof clear spirit.
In a stockpot, add 2500 grams (2½ liters, approx. 10½ cups) cold mineral or filtered water or enough to fill at least halfway. Add 63 grams salt, or about 2.5% salt by weight.
Rinse the chicken parts thoroughly and add them to the stockpot with the smashed ginger, scallion knot and ½ cup of Shaoxing wine. Bring to a boil, uncovered, over medium heat. Once boiling, lower to a simmer and skim the surface foam for a clean broth. The key is doing so quickly before the fats render into oil, which will rise to the surface and bind to the scum, making it harder to separate the two.* Once the foam is removed, add the spice bag. Simmer 1 hour, uncovered. Continue to skim any foam off occasionally. *Oil = flavor. Many spices are oil-soluble, not water-soluble. If you remove the oil, there will not be an effective vessel for the fragrance. Good lushui depends on its oil content. After one hour, in a separate wok/saucepot over low heat, add most of the rock sugar, reserving a small handful (less than a tablespoon) to toss into the stockpot. Let the sugar melt on its own without stirring, until mostly melted and bubbling. Stir until dark red-amber and fully bubbling. Pour a ladleful of broth into the caramel to stop it from cooking further. Stir, then pour caramel into the stockpot and continue simmering. Somewhere around 2-2.5 hours in, the old hen meat gets fall-apart tender and juicy while maintaining a great chew. I like to fish out the meatiest parts to eat/save at this point, strip the carcass and throw back in the bones and skins to continue cooking until it's time to jar the broth.