Aged wines, if they are of good quality, tend to soften and acquire the texture of velvet as the tannins polymerize and form longer chemical chains or bond with pigment and precipitate out of the wine. Acids (mostly tartaric acid) also crystallize and drop out over time, contributing to that softer texture. But I often find that some aged wines seem to gain perceived acidity; they seem tart or sour.
Such was the case with the 2005 Obrien Estates “O” Seduction I opened this weekend—a blend of Cabernet Sauvignon, Merlot, and Cabernet Franc made in the easy-drinking, drink-now style of contemporary Napa Cabs. The visual appearance of the wine was remarkably limpid and bright, with no sign of age. The nose was for the most part what I would expect of a 9 yr. old Napa Cab—still concentrated black berry, chocolate, and freshly- turned earth with the smell of old books just beginning to emerge (which is a good reason to read old books and drink old wines).
But on the palate the bright berry flavors and hints of raisin and an initial medium-bodied velvet texture were quickly over-run by tart acidity. The wine was still enjoyable and the acidity did not harm the meal of grilled chicken that accompanied the wine but much of the enjoyment of aged wines comes from that languorous, slowly–evolving finesse on the finish which in this wine was abruptly cut short like a jack-hammer interrupting an afternoon nap.
So what is going on with this wine? Often aged wines that are past their prime have lost the fruit that balanced the acidity when young. But that is not the case here. There was no lack of fruit—it still had rich, evocative aromas and flavors on the palate but their enjoyment was short-lived due to excessive acidity.
I have two hypotheses. Although tasting notes upon release mentioned firm tannins, after 9 years the tannins were almost imperceptible. Perhaps the wine was a high-acid wine to begin with but in the young wine it was masked by exuberant tannins that had now fallen out too quickly. But the original wine was far from highly acidic—it’s PH of 3.5 is on the modestly low-acid side, typical of Napa Cabs, and it’s titratable acidity was .64 grams, perhaps a bit high for California reds by today’s standards but not excessively so.
My second hypothesis is volatile acidity. All wines contain some acid molecules that are unstable and that are caused by bacteria. This is the acid that eventually turns a wine to vinegar. Well made, properly stored wines, keep those bacteria to a minimum by making sure the wine is not exposed to too much oxygen, which the bacteria need in order to flourish. But as a wine ages in the bottle it picks up some oxygen through the cork. If there is volatile acidity it may increase due to the enhanced oxygen-rich environment.
Usually VA is apparent on the nose—it smells like nail polish remover. I didn’t pick up any of that aroma but perhaps the process had just begun and hadn’t yet modified the aromas. There was a tiny bit of seepage around the cork indicating the seal was not as tight as one would like. But again, the visual appearance did not indicate excessive oxygen which turns the wine first Garnet and then brown.
I think the best explanation is VA but I can’t be sure. At any rate, this bottle was at the end of its life.
Score: It is impossible to score a flawed wine
Price: $60 on release