01 -
Cut grapefruit in half pole-to-pole, then slice into thin half moons.
02 -
In large bowl combine 1 cup water, half the grapefruit, 1 cup blackberries, and 2 tablespoons sage. Mash until broken down.
03 -
Add 3 cups water to muddled mixture. Refrigerate covered for 30 minutes to 1 hour.
04 -
Strain through fine-mesh strainer into pitcher, pressing solids to extract juice.
05 -
Add remaining 4 cups water. Garnish with remaining fruit and sage before serving over ice.