For citrus syrup: In a large saucepan combine the water, orange zest and juice, lemon zest and juice, honey, and ginger. Bring to boiling; stirring to dissolve honey. Reduce heat; simmer, uncovered 10 minutes. Remove from heat. Cover; let cool. Strain; discard solids. Transfer to a container; cover. Chill up to 2 weeks.
Pour 3/4 cup citrus syrup over ice cubes in a glass. Stir in coffee concentrate. Top with orange twist.