Tangerine-Ginger Caipirinhas

1. Divide tangerines or small oranges among 6 tumblers. 2. Add 2 teaspoons sugar and 1/2 teaspoon grated peeled ginger to each glass. 3. Crush the ingredients in the bottom of the glass with a muddler or handle of a wooden spoon. 3. Top each drink with 2 tablespoons tangerine juice and 1/4 cup cachaa (Brazilian sugarcane liquor) or vodka. 4. Fill glasses with ice cubes, stir, and serve.