Soaking oxtail is optional but helps reduce gamey flavor and blood impurities., Cut radish into large chunks to maintain texture during pressure cooking., Natural pressure release preserves meat tenderness and clear broth., Chilling soup overnight helps fat solidify for easy removal, resulting in a leaner broth., Add kombu (dried kelp) during cooking for umami flavor, removing before serving., Mushrooms like shiitake or oyster can be added near the end for extra texture., Add gochugaru or gochujang individually at the table for spice without clouding the broth., Refrigerate leftovers up to 3 days, freeze up to 3 months (preferably broth and meat separately)., Reheat gently on stove; avoid boiling to keep meat tender.