Key points of operation
① Cleaning: put watermelon seeds into rice baskets for elutriation, filter dry, and stir-fry in a pot.
② Slow fry over medium fire: stir fry over medium fire. When you hear the crackling sound, pour the prepared sweet and sour juice into the pot, and then stir fry until dry.
③ Closed container: after the watermelon seeds are cooled, put them into a closed container, drop 5-6 drops of plum essence along the container wall, turn them evenly and seal them for 24 hours.