Note: the older your kimchi, the more sour it will be. My kimchi was relatively fresh. If you are using very aged kimchi, you may need more sugar. I will also suggest adding either bacon, pork belly, or sesame oil (the extra oil helps to temper the sourness of the sauce)- the sesame oil can be added as a finishing oil. If adding bacon or pork belly, add it after sautéing the aromatics but before the kimchi.