1. Peel off the outer skin. Be careful to peel off all the green parts, otherwise it may be a bit bitter. Then cut it crosswise into strips, being careful to cut thinly. Boil it in boiling water, then soak it in cold water for a day or two. During this period, you have to change the water once or twice. When changing the water, be sure to drain the moisture from the skin first, and then put it into new water (this can remove the bitter taste) ).

2. After a day or two, squeeze out the water from the skin, let it dry for a while, and set aside. Then boil some sugar until it becomes watery (you can also put some in if you want to eat chili), put the skin in and cook together for a while. That will make grapefruit candy.