Juicing Grapes

Try this method:
http://www.elise.com/recipes/archives/000107making_grape_juice.php

Yes, I agree, for jelly especially the grapes must be strained and strained well as only the juice is usually used for jelly. Also you might try heating the pulp up (do not boil) as it will cause more juice to be released.

strain the juice through cheesecloth- then you can make whatever kind of jelly you want