Caramel, as you might know, is a mix of toasted sugar and butter. Well, we’ve already covered the butter, so you might not be surprised to learn that the burnt sugar component of caramel also comes from the toasting of wine barrels.
As the wood is toasted, it undergoes the same Maillard reaction that meats, for example, experience through pan-searing. The end result is the formation of toasty or burnt sugar notes!
Personally I prefer my caramel wrapped in Chocolate, dark chocolate at that, but I've been known to suffer through a bag of Rolos!