Combine raspberry juice, lemon juice and pectin in a large saucepot. Bring to a boil, stirring frequently. Add sugar, stirring constantly. Remove from heat. Skim off foam, if necessary. Stir in champagne. Ladle into hot, sterilized “half-pint” jars, leaving 1.4-inch headspace. Adjust caps, and process 5 minutes in boiling water canner. 6 half-pints.