Tart marmalade is delicious on scones or breakfast breads. This recipe produces classic British-style bitter marmalade. If you prefer less bitterness, use only half the grapefruit rind called for in the recipe. Keep in mind that the mixture will thicken as it cools.
2 large thin-skinned oranges
2 medium red grapefruit (about 2 pounds)
2 cups sugar
2 cups water
1/8 teaspoon kosher salt
How to Make It
Carefully remove rind from fruit using a vegetable peeler; discard white pith. Cut rind from 1 orange, 1 grapefruit, and lemon into 1 x 1/4-inch strips. Section fruit; cut into 1-inch pieces. Discard seeds; reserve juice.
Combine all ingredients in a large saucepan; bring to a boil. Reduce heat, and simmer 1 hour or until thick, stirring occasionally. Cool. Pour into airtight containers.
Note: Store marmalade in the refrigerator for up to three weeks.