This is a play on the espresso tonic that my local coffee does in South Philly. They're super refreshing for brunch on a summer day. It plays perfectly with the bitterness of the ingredients. They are also super versatile. While I do a grapefruit and sage version, drinkers can experiment with a multitude of flavor combinations.
in a cocktail shaker, add the Mr. Black, cold brew coffee, and 1 once of the syrup that you just made. Shake well until all ingredients are mixed well. It will take about 1 minute.
pour the contents in the shaker over ice in a tumbler glass.
top off the tumbler with the tonic water
garnish with a grapefruit wedge and spring of sage.
make the grapefruit syrup by heating the grapefruit juice, sugar, two sprigs of sage, and water until the sugar dissolves. Let cool.