Sent by SarahEditor: Nothing beats fresh bread made with a homemade sourdough starter, that's for sure!
However, we've never heard of using red wine in the starter. We're also not entirely sure about this, but we suspect that most of the yeast in wine gets strained out or used up before bottling (or else you'd get fizzy wine, we think?), so there may not actually be any remaining live yeast in your leftover wine.
Here is our favorite way to develop a sourdough starter at home:
Readers, have any of you used red wine in your starters?
Related: Food Science: What is Sourdough?