Cut the grapefruit skin into a proper amount, remove half of the white sac, the white sac part is the source of bitterness, but don't remove too much, remove too much grapefruit sugar will be hard
After cutting, soak in water, add appropriate amount of salt, add salt to remove bitterness, soak for about 10 minutes, remove the grapefruit peel and squeeze the water, then rinse with water, wash it like 3 times to wash clothes, basically eliminate bitterness. Do not wash too many times, will wash off the flavor of grapefruit.
Put a proper amount of water in a non-stick pan, pour in the right amount of rock sugar, rock sugar can be a little more, in order to form a frosting in the later stage, the water should not be too much, can submerge the degree of grapefruit peel, you can cry later.
Put the grapefruit skin in it, boil it on a big fire, stir the rock sugar completely, stir it, put in half a lemon juice, it is ok to put in a little vinegar, in order to make the taste better. Stir well and turn to medium heat to cover the lid, so that the sugar is fully immersed in the grapefruit skin. I am bored for about 15 minutes. I can try enough sweetness during the period. If it is not sweet enough, add some sugar.
The fire is collected from the fire, and the juice is collected while stirring. When you see the bubble at the bottom, the fire continues to turn. Seeing that there is basically no sugar juice, turn off the heat, let cool and start to stir.
Slowly you can see the white frost crystals, continue to turn, until the surface of the frosted sugar covered grapefruit skin can stop, the grapefruit sugar will become, let out cool, pay attention to save, although it can be saved for a long time but after all, no Preservatives are eaten as soon as possible. Once they have done it for a long time, it is quite terrible.