In heat-proof bowl, place yerba maté, sugar, mint, and ginger. Add 3 cups steamed water and stir to dissolve sugar. Let mixture steep for 1 hour or more. Strain mixture to remove solids. Squeeze juice of grapefruit into maté mixture. Chill mixture for 2 hours or more.

For individual drinks, place a couple of ice cubes in glass and fill halfway with maté mixture. Fill rest of glass with club soda.