Cut lemon into 12 paper-thin slices; discard seeds and ends of rind.
Bring a medium saucepan of water to a rolling boil.
Remove from heat, and add lemon slices; stir until softened, about 1 minute. Drain, and immediately plunge slices into ice-water bath. Drain.
Bring sugar and 1 cup water to a boil in a medium skillet, swirling to dissolve sugar.
When liquid is clear and bubbling, reduce heat to medium-low. Add lemon slices, arranging them in one layer with tongs. Simmer (do not let boil) until rinds are translucent, about 1 hour.
Transfer to a baking sheet lined with parchment. Let stand until ready to serve.
Cut a round of parchment paper to fit just inside a medium pot; set aside.
Bring sugar and 3 cups water to a simmer in pot, stirring until sugar has dissolved.
When liquid is clear and ubbling, reduce heat to medium-low.
Add citrus slices, arranging them in a slightly overlapping layer.
Cover with the parchment paper round. Place a cake pan on top of parchment to keep slices submerged. Simmer (do not boil) until rinds are almost translucent, about 40 minutes.
Let cool completely in syrup.
Candied citrus slices can be stored in syrup up to 1 week.
Line a baking sheet with parchment paper; set a wire rack over sheet. Transfer candied citrus to rack. Let stand until dry and slightly firm, about 8 hours.
Peeled the skin with a vegetable peeler
bring cold water and peel to a rolling boil. Drain. Repeat. For orange peel, I might do this one or two times; for grapefruit, 6 or 7. Taste it. When the peel is tender, cook it in the sugar syrup.
drain off the boiling water, refill with cold water and bring to a boil again. The more you repeat this step, the less bitter it will be. Be careful, though, because too much boiling will render your candy tasteless. 2-3 times is usually
Bring sugar and 2 cups water to a rolling boil in a medium-size, heavy skillet, swirling skillet to dissolve sugar.
When liquid is clear and bubbly, reduce heat to medium-low.
Add lemon slices in a single layer.
Simmer until rinds are translucent, 30 to 35 minutes.
The lemon peel was sticky so I dipped it in sugar and that made it easier to chop.
Transfer to baking sheets lined with parchment paper. Let cool completely.
I allow the candy to dry out until it's tacky, then toss it with sugar to finish it. (You can use colored and/or flavored sugar too.) This allows me to store it dry in containers without it getting sticky. You can dry it in a cool oven (200 degrees or less) or simply let it sit out for a few hours.
