Napacat . . . that's strange to hear about the Eucalyptus note on the Mascot.
I've had the 2009 a few times now and a bottle of the 2010.
Unlike Bomba, I actually have enjoyed these on day one with ~4 hour decant (but that's pretty standard for my tastes and enjoyment of young new world wines)
It definitely has a ripe dark red cherry / strawberry nose with some secondary earth elements that bring some nice balance to the wine, but I have never gotten a mint/eucalyptus anything from this wine.
To put this in perspective, if you look at the vineyards where Mascot sources from (they do take juice deemed not up to Harlan snuff), I do not believe there are any eucalyptus trees that high up on the ridge above Oakville where the vineyards sit. In dramatic comparison, almost directly below the Harlan vineyards sit Heitz's Martha's Vineyard vines which are flanked by Eucalyptus trees.
Based on a terroir philosophy, some of the dominant flavor profiles of these two wines -Harlan / Mascot vs. Heitz MV makes sense. Heitz MV is flanked by Eucalyptus. A good part of the ridge where Harlan is grown used to be devoted to cherry orchards. There's no scientific proof that there is a connection between these previous/current plantings and the characteristics that make it into the wine, but it seems like an awfully large coincidence for there to be no connection!
That said, there has been some speculation about the eucalyptus/minty characteristic of Heitz MV. Some have suggested that if the tiniest bit of eucalyptus leaves made it into harvest, the oils from those leaves would have a profound and broad affect on the resulting wine.
So, I guess it's possible that somehow some eucalyptus debris / leaves got into some of the Harlan harvest (a nice hard uphill wine would be all that it would take). But, again, I have never gotten that at all from the Mascot