Grapefruit and orange peel work well too. Be sure to use organic fruit and to scrub them well.
5-6 organic lemons, about 1 1/2 pounds
1 teaspoon salt
1 1/2 cup cold water
2 cups sugar
Superfine sugar (optional)
Peel the lemons with vegetable peeler, taking off long, thin strips. Fill a medium sauce pan 3/4 full with water and 1/2 teaspoon salt. Add the lemon peels and bring to a boil. Simmer for 10 minutes, then drain. Repeat, using the other 1/2 teaspoon of salt. This is softening the lemon peels and taking away the residual bitterness of the white pith.
Drain the peels for a second time and set aside. Add the cold water and two cups sugar to the saucepan and bring to a simmer, stirring until the sugar dissolves. When the sugar dissolves add the lemon peels and simmer on low for 45-60 minutes. Watch near the end to make sure the sugar doesn't caramelize.
Immediately lift out the peels with a fork and let them cool on a piece of wax paper that has been sprayed with cooking spray. If you want to eat them as candy, roll them in superfine sugar while they are still wet. When they have cooled and dried put in a sealed container in the refrigerator, where they will last for quite a long time. The syrup can also be stored in the fridge and used for flavoring and sweetening.