Step 1

Build in a white-wine glass or large cocktail coupe. Add the sparkling wine first, then the remaining ingredients. Swirl the drink gently to combine.

Step 2

Wash the grapefruits thoroughly with soap, water, and a scrubby sponge. Towel dry. Use a vegetable peeler to peel the grapefruit zest into strips. Combine the peels and sugar in a resealable plastic or silicone bag. Compress the air out and let sit for 12 to 16 hours at room temperature, massaging the mixture every few hours to extract the oils from the peels. You’ll know it’s ready when the peels are translucent and the sugar is gooey.

Step 3

Meanwhile, combine the tea, jasmine ball, and water in a small container and let sit for 12 hours in the refrigerator. After 12 hours remove the solids and let the infusion reach room temperature.

Step 4

Stir together the tea infusion and the grapefruit sugar mixture, then strain through a fine-mesh filter or sieve. This syrup will keep in the refrigerator for up to 1 week, or 4 weeks if frozen.