In a small bowl, soften the gelatin in 3 tablespoons of the water. In a saucepan, heat the remaining water over low heat and add the gelatin. Stir until the gelatin dissolves and add the sugar, lemon zest, and juice. Heat to just below the boil and remove from the heat. Cover and let steep for 20 minutes.
Strain the liquid through a fine sieve into a shallow metal bowl. Discard the lemon zest and leave the liquid to cool. Watch it carefully and, when it is quite cool and just about to set, stir in the champagne. Pour into perfectly clean tall champagne flutes and drop a few raspberries into each. Chill until cold and serve, garnished with a few more raspberries and a sprig of mint.
c.1997, M.S. Milliken & S. Feniger, all rights reserved