For some reason, I wrote in my notes from the Cooley trip last year that the recent Mallorcan wine-finished Tyrconnell was maturing in a poplar cask. It's clearly oak so I don't know where that came from. Anybody else take notes that day? Who mentioned poplar? And is a poplar cask even possible?
That reminded me that the laws defining Irish whiskey don't specify oak, just wood. Do we know of any whiskey matured or finished in a cask not made of oak?