Preparation Scoop ice cream into an 8x4x2 1/2" loaf pan; pack ice cream along one long side to fill half of pan. Cover and freeze until firm, at least 1 hour. Meanwhile, bring sugar and 1 1/4 cups water to a boil in a small pot, stirring to dissolve sugar. Remove from heat; add tea bags and zest. Let steep for 10 minutes. Remove tea bags; discard. Stir in grapefruit juice. Cover and chill grapefruit mixture until cold, about 1 hour. Process grapefruit mixture in an ice cream maker according to manufacturer's instructions. Pour sorbet into empty side of pan alongside ice cream. Cover and freeze until firm, about 2 hours. To serve, spoon across ice cream and sorbet to form swirled scoops.
Preparation Scoop ice cream into an 8x4x2 1/2" loaf pan; pack ice cream along one long side to fill half of pan. Cover and freeze until firm, at least 1 hour. Meanwhile, bring sugar and 1 1/4 cups water to a boil in a small pot, stirring to dissolve sugar. Remove from heat; add tea bags and zest. Let steep for 10 minutes. Remove tea bags; discard. Stir in grapefruit juice. Cover and chill grapefruit mixture until cold, about 1 hour. Process grapefruit mixture in an ice cream maker according to manufacturer's instructions. Pour sorbet into empty side of pan alongside ice cream. Cover and freeze until firm, about 2 hours. To serve, spoon across ice cream and sorbet to form swirled scoops.