Rum barrel Big Sound. A little tart, this is the beer CCB allegedly botched. A lot of people seem to finding these tart but in differing degrees. CCB's even offering refunds for people who are not happy with it.
Here's the blog post about it (click on the link to go back to post # 19):
http://www.cigarcitybrewing.com/index.php?option=com_easyblog&view=entry&id=21&Itemid=37