I want to make a cranberry cider, but I’m not sure how to proceed. I have 5 1/2 gallons in primary right now. I want to add 6 pounds of cranberries to the secondary. Do I purée them? Cook them? Purée them, and cook them, or just heat to pasteurize? Also how long do I leave in secondary?
Rinse, freeze, chop in food processor when ready. the freezing will break the cell walls and make the chopping easier. No need to cook. I estimate you will need 5-6 bags of whole berries.
Good call on freezing them. Don’t heat them or you will end up with pectin haze.
Wow that much, guess I under estimated, thanks.
If you have access to the big warehouse food outlets (BJ’s, Costco, etc.), this is the time of year they sell the whole fresh berries in the big bags pretty cheap (4 or 5 lbs, maybe, it has been while since I bought the big bag). If you buy them out of the freezer section, I believe those have been flash-frozen which means that the cell walls don’t get broken up very much and you don’t derive as much benefit than if you froze them yourself. If you thaw a bag of frozen fruit and you end up with a sloppy mess, then either it wasn’t flash-frozen, or it had thawed somewhere between the factory and the freezer.
pectin haze isn’t a huge problem, just add some pectic enzyme. you can find it at your LHBS and it’s fairly cheap.
I would recommend putting the purée ina paint bag as well. Much easier to remove the bag of pulp from the liquid than remove the liquid from the pulp 
Beware that ‘bag’ is not a standard unit of measure. Also, if you freeze them you really don’t need to chop them.
So 18lbs is too much?
Sorry, standard supermarket bag is 12 oz, so 60 - 72 or so ounces.