- 3 pounds tangerines (about 18), unpeeled, washed, ends trimmed, and cut crosswise into thin slices
- 4 cups sugar
- Place a small plate in freezer. In a large pot, bring tangerines and 6 cups water to a boil over high. Reduce heat to medium and cook at a rapid simmer until tangerine peels are tender, 20 minutes.
- Add sugar, increase heat to medium-high, and stir until sugar dissolves. Return to a boil and cook, stirring often, until mixture is thick and darkens slightly, 40 to 45 minutes. To test for doneness, drop a spoonful on frozen plate and freeze 2 minutes. Marmalade is done if it has a slight film that wrinkles when pushed with a finger. If it spreads out and thins immediately, continue cooking. Transfer marmalade to airtight containers, cover, and let cool completely.
To store, refrigerate marmalade up to 1 month, or freeze, up to 6 months.