Grapefruit Soda with Chai Masala

My husband loves grapefruit, so one year I surprised him with a dwarf Ruby Red Grapefruit plant. The little plant is housed in a big pot only a few feet high but bears impressively large, orb-like yellow citrus that are extremely fragrant when sliced. Sometimes I collect the juice and stir it into a simple syrup made with chai masala (tea spices). I infuse whole spices rather than ground into the simple syrup to get a lighter flavor that delicately complements the citrus.