Best basic sparkling–wine tour: Mumm Napa
An articulate guide covers every aspect of the process in memorable terms; videos give you close-ups of things you otherwise
can’t see, like harvesting and the madly foaming surface of a fermenting tank of wine; and cool props show up too, like a
wine bottle tacked sideways to the wall that lets you peer at the yeast settled there, flavoring the wine.
Plus, the tour is free.