Just like wine, wine vinegars can be red or white and just like wine the quality is determined by the type of wine used. Fine vinegars come from fine wine and are made the slow , traditional way in oak barrels. They are matured in wood for periods ranging from a few weeks to one to two years.
Generally speaking red wine vinegars are aged longer than those made from white wine. The very best wine vinegars are made in relatively small batches, they have fine balance and subtle , complex flavour. They are characteristically rich and mellow.
Commercially produced wine vinegars are of an inferior quality, using average wine and faster production techniques that remove a lot of the more subtle flavours in the wine. Many commercially produced wines are still very good, and as with so many things, the price reflects the quality.