1 bottle dry white wine, such as Pinot Grigio (750 ml)
1 cup grapefruit liqueur, such as Campari
2 lemons, thinly sliced, seeds discarded
2 oranges, thinly sliced, seeds discarded
Ice cubes, as needed
1 bottle club soda or seltzer water (1 liter)
In a large pitcher, combine the wine, grapefruit liqueur and citrus slices. Refrigerate the punch until ready to serve (the sangria can be refrigerated up to 2 days).
To serve, fill glasses with ice, then fill them 3/4 full with the punch and top off with a splash of club soda or seltzer water.