What do you do with press runnings!

Hi, terribly new to the sport of wine making. I purchased some Prem. Cab grapes over the weekend and have gotten to point of pitching yeast. I'm following my LHBS printout and have a question about press runnings and topping off the carboy. So..

1) I understand the concept of free runnings and seperating them before you press. My question is what do you do with press runnings? And how/when do you blend them back?

2) When fermenting and aging what am I to top off the carboy with? I really want to stay true to the purity of the variety/crush and not top with bottled cab?

Thanks in advance.

As for topping off...

...what's more true to the history and tradition of wine than a blend? It is totally fine to use a previous batch of wine, or a commercial version of the same type.

If you absolutely don't want to do that, and you want to be what you consider to be absolutely true to the recipe/whatever, you can:
- select a smaller carboy and discard the excess
(or freeze it for topping off subsequent batches)
- top off with water

Water will dilute the flavor, but the wine will be just fine regardless. Boil the water and let it cool, though, so that you're not dumping a whole bunch of oxygen in there along with the water, which would kinda defeat the purpose of filling up the headspace.

Bump