A salted duck egg is a whole duck egg cured in brine or a salt-and-clay paste until the white turns intensely salty and the yolk sets firm, deep orange and oily. The prized part is that grainy, umami-rich yolk, which crumbles like fudge and weeps golden fat — the jewel folded into mooncakes, mashed over rice porridge, or steamed into custards and stir-fries across China and Southeast Asia. It is one of the oldest and most beloved ways of preserving the rich duck egg.