Separating Tomato Pulp From Water

[Father'sDaughter]

I've seen where some have mentioned the practice of letting the uncooked, milled purée sit overnight to allow the liquid to separate from the pulp. I also remembering someone cautioning against starting with warm tomatoes as it could start fermenting while it sits.

So my first question is, should the purée be placed in the fridge while it sits, or should I find a cool place somewhere in my house?

As for covering it while it sits -- loosely so it can breathe, or tightly?

Thanks!