Complex sentence: Semi-fermented pomace is produced during rosé wine vinification, where the pomace is removed before the fermentation period is completed, and virgin pomace, which is produced during white wine vinification, is not fermented at all.
Split into simpler sentences: Semi-fermented pomace is produced during rosé wine vinification, where the pomace is removed before fermentation is complete. Virgin pomace, which is produced during white wine vinification, is not fermented at all.