Directions :

1. In a large saucepan, bring 4 cups water to a boil. Add lemon slices; cook, uncovered, 2-3 minutes. Remove lemon slices and immediately drop into ice water. Drain and pat dry.
2. In same clean saucepan, combine sugar and 1 cup water. Bring to a boil, then reduce to a simmer; stir until sugar has dissolved, 3-4 minutes. Add lemon slices. Simmer on medium-low, uncovered, until lemon slices are translucent, 30-35 minutes. Remove lemon slices with a slotted spoon; line in a single layer on a 15x10x1-in. sheet pan lined with parchment paper; discard liquid. Let dry overnight. Store in an airtight container.
3. If desired, toss dried slices in additional sugar. Let dry 2-3 days on baking sheets. For crisp slices, dehydrate according to manufactures' directions.