I mean…i cant promise you that it is, but id be VERY surprised if Mike O pegged these vines incorrectly.
Have you ever had a CA Mondeuse? Because this is what it tastes like, and a quick look at the other TNs seem pretty well aligned (including those from @Frank_Murray_III @brigcampbell @Chris_Seiber 
Unfortunately I have not, but only for the simple reason that I have never had the chance. I definitely want to try one, not sure if any is imported to the EU though.
There’s not much Deuce in the states.
Lagier Meredith of coarse, some in Bien Nacido, a bit in the Sierra Foothills and a smattering here and there.
I believe Mondeuse is also the number 2 variety, behind Negrette but ahead of Zinfandel, at the Oakville Farmhouse Vineyard, but of course Bedrock just makes the one field blend, not a varietal Mondeuse.
Yet another example of why you should never listen to a single thing that i say, ha!
Might even pour myself a celebratory glass of 10.5% ABV Savoie Mondeuse.
Well, if it wasn’t Mondeuse, how about 2012 Lagier Meredith Mondeuse, which I still have and I believe is a Berserkerday wine?
And if you want weirdos from Carlisle, how about 2011 Carlisle Grand Noir (Dommen Ranch).
In the 1860’s, they planted in the JacksonVnyd in SierraFoothills, Mondeuse (and Refosco). In the 1960’s, when the harvested some grape cuttings out of that abandoned Vnyd, based on an old map of that 1800’s era they had found in the UC/Berkeley library (where the O&V school used to be) the Refosco variety. It was distributed by FPS for yrs as Refosco. Turns out they had misread that old map and the FPS Refosco turned out, by DNA, to be Mondeuse. So most of the Calif Refosco planted in the 1970’s was actually Mondeuse. Of course, the Pelletti/Carlisle Mondeuse predates that & was not coming thru Jackson.
Here in NM, Paola d’Andrea/Deming planted Refosco. But all of the wines made from his Refosco sure as hell taste like Mondeuse. He won’t do the DNA on his Refosco.
SteveMatthiasson’s Refosco came directly from Friuli in his suitcase.
Now you know the rest of the story. FWIW.
Tom
So, in essence, you really don’t know which variety you are drinking when you’re having an obscure variety from California! 
Can’t remember how many stories I’ve read how somebody has planted some rather obscure variety somewhere, but it was misidentified or mislabeled and it turned out to be some completely different but equally obscure variety! Or just Zinfandel. 
(And even Zinfandel itself is a story of its own…)
I really should have drunk this before learning that it’s not mondeuse.
We’ve all had times we waited too long to open a bottle, but I may be the first to regret it for this reason.
I hear you buddy! I am now looking forward to opening my 01 a great deal less 
Years ago, Mike Officer told me he would occasionally send cuttings to a lab somewhere to do DNA testing to find out what a particular vine was, but it was expensive so he didn’t do it very often. He said that he once sent in cuttings from a particular old vineyard and the lab’s response was, “we have no idea. It’s probably a cross between X and Y, but we really don’t know for sure.”
Two Acres has some funky stuff in it.
A true gem in Sonoma County! There is little old-vine Mourvèdre in Sonoma County. Yet, here we have two acres of predominantly Mourvèdre planted in 1910. Other varieties planted include Petite Sirah (10%), Syrah (6%), Carignan (4%), Peloursin (3%), and Alicante Bouschet (2%). There are also a few Zinfandel vines in addition to nine whites of a variety called Helena (a white cross of Zinfandel and Mondeuse noir).
How about some Helena!
Apparently I need to be more careful of what I say. I should be cleaning barrels right now but feel the need to address this, lest people think I’m dishonest and willing to slap any variety on a label.
When I started trying to identify all the varieties at Two Acres in 1997, there was one variety (100 vines to be exact) that I could not figure out. In 1999, we sent cuttings to Professor Andy Walker at Davis (he was considered the country’s best ampelographer of the time) to help us out. He said it was Mondeuse. Hence, we went with that and made one barrel of it in '99, '00, '02, and '03. A decade later, when genetic testing became available (and I’m always happy to pay for the analysis on anything that is not clearly obvious), we had it tested. It came back as Calzin, a cross of Mondeuse and Zinfandel. At that point we removed the vines and replanted to Syrah.
This is super helpful - thanks for the context Mike! Either way, the wine was awesome! And hey…sounds like it’s ‘kinda’ Mondeuse…so that’s good enough for me, ha! 
Our Mondeuse vines here at Lagier Meredith are the real deal. We got the budwood in 2007, directly from vines at UC Davis that we had DNA tested several years earlier in my research laboratory and compared to DNA from authentic Mondeuse in France. (When Steve and I decided we wanted to plant some Mondeuse, I already knew that getting budwood from a commercial California vineyard would be risky because of all the ID mixups so that’s why we went with the authenticated UC Davis material.)
If I recall correctly, it was seeing the Mondeuse vines here in our vineyard that prompted Mike Officer to question the identity of his own vines and then send samples to UC Davis for DNA testing. (Is that correct @M_Officer ?)
I still have a bottle of the 1999 Carlisle Mondeuse and I’ve been meaning to get to it. Calzin is a new one for me for sure, so now I’m even more excited.