I've heard of winemakers removing a small amount of must prior to
fermentation. They add it back to the wine later to enhance flavour.
A couple questions:

1. How much is a reasonable amount? A cup? A litre?
2. Storage tips? Presumably frozen in a sanitized plastic pop
container.
3. At what stage in the process is the juice added back?
4. Is there a meaningful bouquet/flavour benefit to this procedure?
5. Sorbate required? I assume yes.
6. I assume this will produce an "off dry" wine. Would this
procedure then be undesirable for most reds?

I guess that was more than "a couple" questions.

Thanks, Jim