In a small bowl, mix the sugar and hot water until the sugar is dissolved. Add the apricot preserves.
Remove pit from the pickled plum and add to the bowl. The plum is very soft and should fall apart. Then add ½ teaspoon liquid from the pickled plum jar, soy sauce and rice vinegar.
Mix everything together with a fork until the duck sauce is well-combined. Let the sauce sit for 5 minutes and mix again.
Feel free to adjust this duck sauce recipe to your own tastes. You can add more sugar or apricot preserves if you like the sauce sweeter. Add more rice vinegar if you like your sauce slightly tart. You can also thin it out further with a little bit of hot water if you’d like a thinner consistency.This duck sauce should last in the fridge for several months.