Fill your punch bowl or large pitcher with dry white wine. Make a bundle with the sprigs of sweet woodruff, tie the bundle to a stirring spoon that you lay across your pitcher or bowl. The leaves of the sweet woodruff should be submerged in the wine while the stems should not (the stems have a bitter taste, and you don’t want your May wine bitter). Remove the sprigs after 30 minutes and add the cold champagne.
Note: Make your ice ring a few days ahead of serving May Punch in order for it to freeze. Consider adding any edible herbs and flowers to the ice ring.