Bottle shock is the bane (or at least one of the banes) of my existence.

What is bottle shock? I can honestly say that, having tried to educate myself on this subject, I really don’t have a clue, or at least a clue I have any faith in. I know what it does. It makes the wine (primarily red wines) pretty unpalatable for a period of time after bottling.

But what causes it? If you do an online search, you’ll find a plethora of information, much of it going off in entirely different directions, and all having in common only the fact that they don’t seem to be based on anything at all. The most common explanation seems to be that bottle shock is due to the wine picking up oxygen in the bottling process. Though there are also statements indicating that the problem is the opposite, the wine having trouble adapting to its new, oxygen deprived, environment inside the bottle.

I’ve talked to various people, most notably winemakers and the lead technician for our cork supplier, to try to get some insight into what causes bottle shock, and, more importantly, what can be done to minimize its impact. The result of my hours of inquiry: Nada.

So while we’re on the subject of its impact, what is its impact? Again, no real answer. Often, the fruit simply disappears, leaving an acidic/tannic brew that isn’t much good for anything, especially drinking. Even worse, you can get a cacophony of unpleasant scents that more resemble a witches’ brew than anything you’d want to have with dinner.

At one point, I thought that the more tannic and bold the wine, the more likely the bottle shock will be severe and long-lasting. But several bottlings of bigger wines that experienced little in the way of bottle shock have led me to abandon this hypothesis.

When I say bottle shock can be “long lasting”, what is “long lasting”? Again, it’s very variable. Our Sly Dob Cabernet Sauvignon 2005 took a year and a half to get over its bottle shock. Our Seven Artisans Meritage just as long.  But our latest bottlings of Syrah and Petite Sirah showed little evidence of bottle shock. It certainly seems that our Bordeaux variety wines seem to have a bigger bottle shock problem, but whether that’s just coincidence (as I think more likely) or something else, I can’t be sure.

These are some of the other things I’ve heard from people who I respect concerning bottle shock:

It’s worse when you filter (as most wineries do), since the filtration process not only disturbs the wine chemistry, but introduces oxygen into the wine. I’ve heard this enough that I’m inclined to give it some credence. On the other hand, whenever I’ve tasted wine going into the filter and coming out, I’ve never noticed much, if any, difference. True, bottle shock tends to not show up for several weeks, or more, after bottling, for reasons that are not at all apparent. So maybe the filtered wine is shocked, but hasn’t shown the telltale symptoms yet.  And to add an extra wrinkle, when I take a tank or barrel sample, which lets in far more oxygen than any filtration/bottling process, I’ve never experienced anything remotely similar to bottle shock.  So, ultimately, I’m inclined to discount the oxygen theory.

Another possibility, mentioned above, is that the shock comes from the oxygen starved environment in the bottle. Since some of the off-odors you get from bottle shock are of this (reductive) type, this makes some sense. Adopting this theory, we tried using two different types of corks in one bottling, one of which let in more oxygen than the other, to see if they were different. (In both cases, the amount of oxygen let in was tiny, but was tinier in one case than the other.) We tried opening them a few months after bottling. No difference (lots of bottle shock in both). We repeated the experiment about a year after bottling. This time there was a big difference. Two of us found the higher oxygen corked wine to be much better. But the third of us found of the wine with lower oxygen cork to be the better one. Go figure. At least we all found there to be a difference, albeit a difference that doesn’t offer much guidance for the future.

The other thing that seems to be the case is that wines that have severe bottle shock don’t travel as well. Whether this is a matter of the travel re-introducing the bottle shock that had passed away sitting in the warehouse, I can’t tell. Adding to the difficulty is that I have to rely on reports from people on the other side of the continent, since I’m not there to taste the wines.

Ultimately, I’m inclined to think the problem is a combination of things, which makes it even harder to sort out.  But I’m not even sure of this.

Alas, and this is but one of the many aspects of winemaking that raise so many questions, for which there are so few answers.

This entry was posted on Friday, February 26th, 2010 at 7:23 am and is filed under Winemaking. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.