Hi Cat,
Welcome to All Things Plants! We're glad to have you here.
If you are using seeded grapes, no matter the size and no matter what you are making, your best bet is to smush them up (think potato masher) and strain them through a couple layers of cheesecloth, or through a strainer and then through the cheesecloth. The seeds won't really hurt anything, but the strainer keeps them away from your final product. I always smush and strain for grape juice and jelly.
Hope this helps!
