I've noticed in my infancy stages of playing with solera and beer, that the first
exposure of the barrel to the beer, results in a fairly rapid mainfestation of the Oak
Flavor....I left a BSD in for 1 month...and it has a nice oakiness. It would not
take too much exposure on a new barrel to over oak your beer IMO.
My barrel had red wine in the oak and it went well with the dark Belgian ale.