Step 1

Cut each grapefruit and half and juice them. (Reserve the juice for another purpose.) Use a soup spoon to scrape out the pulp and membranes.

Step 2

Use a chef's knife to cut the grapefruit peels into strips just shy of 1/2-inch (1,25cm) wide. Place the peels in a large pot and cover with water. Bring to a boil and simmer 5 minutes.

Step 3

Drain the peels and repeat the simmering and draining process with the grapefruit peels one more time.

Step 4

After you've blanched the peels three times, place them back in the pot fitted with a candy thermometer, if using. Add the sugar, water, and corn syrup and bring the mixture to a boil.

Step 5

Reduce the heat to a low boil and cook the peels until they're translucent and glossy. The temperature should read about 218ºF (103ºC) and should take about 45 minutes. If you're not using a thermometer, it should look like the 7th photo in the post.

Step 6

Drain the peels in a colander then spread them on a wire cooling and let sit 12 hours at room temperature to dry out a bit.

Step 7

Sprinkle some sugar on a baking sheet (about 1/3 cup, 65g) and use your hands to toss the candied peel in the sugar, adding more sugar as needed, and shaking off any excess, until the peels are well-coated and no longer feel sticky.