Lemon-Ginger Brew

Pulse 8 ounces ginger, peeled and chopped, in a food processor to a coarse paste. Bring ginger and 6 cups water to a boil in a medium saucepan; reduce heat and simmer until reduced to 3 cups, 30 –40 minutes. Strain into a large jar and mix in 1/2 cup lemon juice and 1/3 cup agave syrup or pure maple syrup; add more lemon juice or agave, if desired. Let cool; cover and chill. Do ahead: Brew can be made 2 weeks ahead. Keep chilled.