Prepare boiling water canner. Heat jars and lids in simmering water until ready for use. Do not boil. Set bands aside.
Combine raspberry juice and lemon juice in a large saucepan. Gradually stir in pectin. Bring to a boil over high heat, stirring frequently. Add sugar and return to a full rolling boil that cannot be stirred down, stirring constantly. Boil hard for 1 minute, stirring constantly. Remove from heat. Stir in champagne. Skim off foam if necessary.
Ladle hot into hot jars leaving 1 /4 inch. Wipe rim. Center lid on jar. Apply band until it's fingertip tight.
Process in a boiling boiling water canner for 10 minutes, adjusting for altitude. Check lids for seal after 24 hours. Lids should not flex up and down when center is pressed.