I don't think I've ever worked so hard trying to figure out what is going on in a bottle of wine as with this one. My real education began in July on the two rpm tours, and this has only extended it.
Recently given the opportunity to pull a cork on a bottle of 2009 Mirage Reserve CS, the first thing I couldn't help but notice was fizz, lots of fizz; in a cab. Also noticed the cork was surprisingly soft and came out quite easily, but no signs of seepage. Humm, not what I'd normally expect, but I've read comments on earlier Woot! cab offerings where this fizz was also reported, and can confirm, having pulled a cork on that one too, but this really seems excessive.
Day one: fizzy, I knew this, now deal with it. Decanted 1/2 into a 375ml and capped with Argon and back into the chiller. Poured a good sized taste, recorked the 750, no Ar, and back to the chiller with it too.
Funk, plenty of that, perhaps too much; so the glass will set awhile to see if it blows off. A couple hours later, less funk, less fizz, but both still right there. Can't get much nose beyond the barnyard, perhaps some muted fruit. Gave it a taste and and got a sharp bite on the tongue. Seems like a mix of something acidic and tannic, both at the same time, and that funk, just hanging around for a long time.
Day two: left the 375 alone and returned to the 750. Went to pull the cork and it nearly ejected itself! Fine. ICFT. Venturi time; into a carafe, back into the bottle, back to the carafe, back to the bottle. Cork and shake the bottle. Wow, an inch of foam. Back to the carafe to let it settle down for a few hours.
Fizz gone!
Funk diminished, but remains. Taste profile pretty much the same.
What would cause this…?
Here is where my education continued, at least four hours of research and some possibilities emerge.
Day three: I dug a cousin bottle out of the cellar for comparison and pour three glasses; some 750, some 375 and the 2009 cousin. Just the slightest hint of fizz in the cousin, but also a bit of that barnyard, way in the background. Still right out there on the Mirage, diminished on the 750 and unchanged with the 375 that was still fizzing right along. Recorked the 750, the 375 and cousin with Ar and back to the chiller. The Mirage still funk on the nose, sharp on the tongue, not much fruit and that long strange tannic finish. Cousin was doing well.
Day four: today, looking to confirm what I think I may have learned in my research.
The 750 had calmed down a bit more, and to some may be considered passable, not so with the still fizzy 375. That Argon really does work!
My conclusion: flawed bottle, at least the one I was working with, exhibiting what seems, to me, to be a textbook example of a Brettanomyces-infected wine. Mind you I could be totally wrong, and invite opinions.
I really want to like this, it's a cab, and affordable cab at that, but more importantly I really wanted to understand as best I could what was going on that made this so unique in wines I've encountered. In that I believe I succeeded.
While Brett, a yeast, in excess, is considered a flaw, at low concentrations it seems to be accepted and at times even encouraged. My research seemed to confirm what I was tasting; excessive barnyard, diminished fruit, acidic or metallic taste that, for me, just made this an unbalanced bottle. From my reading, brett forms most easily in higher pH (lower acid) wines that may have been more highly extracted as is now so common, add a bit of RS, and MLF, and the yeast produces CO2 as it develops, that fizz. The infection can easily be picked up while aging in wood, but also just from contaminated equipment. It may not be detectable at bottling, but as it is slow growing it can take time to fully develop to easily detectable levels, and storage at ~20C is ideal. This would explain why earlier CT notes of made no mention of this being at all bretty; hadn't yet had time to flourish in a warehouse.
Likely I'm just overly sensitive and YMMV, but for me this bottle was initially excessive, but it did evolve with help, perhaps for others, and more importantly other bottles that may vary considerably, it's not so much an issue. Google some combination of "wine, brett, taste, flaw" and you'll get a wealth of information with which to make your own decision.