What does Edgar Allan Poe mean by virtuoso spirit?

He means that few Italians are true connoisseurs, or supreme masters, of wine. Don't shoot the messenger.

Another answer: I would disagree. I think what he meant is more subtle. A virtuoso is someone with a special knowledge, skill and passion in a particular area. Poe is saying that most Italians have no capacity for this depth of engagement with any one thing. Personally, I think Poe was wrong too!