In this corner, weighing in at a mighty 225 pounds, hailing from Portugal, Cork 'The Natural' Closure! And in the opposite corner, cresting the scales at 217 pounds and rising...Screw 'Twisty' Cap!
Spend much time around wine nuts these days, and the conversation eventually steers to any one of a number of renditions of the above. And though we're fully appreciative of the significance of the debate, we wouldn't mind a little more civilized approach to the discussion.
So here's the rub: cork has been the seal of choice for hundreds of years, but it has a tendency to become contaminated. Screwcaps, relative newcomers but becoming immensely popular, eliminate contamination but among other disadvantages, certainly lack romance.
So which is better?
The answer, like most things in life, isn't cut and dry. We have chosen screwcaps, and very much believe in them, but it wasn't an easy decision. We will do our best to spell out the pros and cons of each, and then lay out our case for why we have chosen screwcaps. In the end, it is very much your choice as to which, if any, best suits your lifestyle.
Cork has been around for hundreds of years. It is sort of like nature's bubble wrap-cork is essentially a mass of cellulose encompassed air pockets. It is very spongy and is largely inert to wine, at least for a decade or two. This is an interesting point. Wine's unique combination of alcohol and acidity makes it pretty corrosive. We've watched a leaky tank eat right through 'chemical resistant coatings' on concrete floors in a matter of days. So cork's ability to withstand this onslaught shouldn't be underestimated. Cork in and of itself doesn't have much affect on the taste or aroma of wine, but for hundreds of years, it's unsanitary handling led to many a spoiled wine. Unfortunately, modern day sanitation techniques, which have greatly eliminated much of these problems, come with their own baggage. The most common means of sanitation involves a chlorine bleach process. Sadly for us winos, all wood products have the potential to contain a bacteria that when in the presence of chlorine creates a compound called trichlorianisole, or TCA for short. TCA isn't the least bit harmful, but it stinks to high heaven. In fact, olfactory wise, it is the single most intense compound in the world, able to illicit responses in the parts per trillion (ppt) range. And of course, corks contaminated with TCA will also contaminate the wine they are sealing. The old adage is, “the cork should smell like wine but the wine should not smell like cork”. So, despite all sorts of grand intents, it is invariable that some cork will become contaminated. How much is contaminated is another great debate, and we will get to that in a minute.
Screwcaps have been around for decades. They are notable for sealing the likes of Mad Dog 20/20 and Boone's Farm, so they have been known to suffer from frequent cases of 'iwouldrathernotitis'. Screwcaps maintain their seal by means of either a tin or polyethylene liner. The polyethylene liner has some small amount of permeability, while the tin does not. As there is no wood present, TCA is not a problem, but there may or may not be problems with the permeability factors. Some people believe that the polyethylene liner allows for too much 'breathing', thus aging a wine prematurely. Some believe that the tin liner doesn't allow for enough permeability, leading to reductive wines (wines that suffer from lack of oxygen exposure often exhibit sulfur like aromas and are called referred to as reductive). There is also a small, but significant camp of folk who believe that the liners used in screwcaps are not 'inert', that is, wine's complex chemical constituency leaches out some small part of the components of the liner.
So as we can see, neither closure is 'perfect'. The trick then, is choosing the lesser of two evils. For us, that was the screwcap.
In 2002, Sean dealt with a situation that forever changed his opinion of corks. While coordinating cork quality control, the following situation (presented in his own words) unfolded.
“We had analyzed several batches of corks from a couple of suppliers and had chosen a lot of corks from a supplier we had a good relationship with. Our sensory sampling led us to conclude that these corks had less than a 2% chance of TCA contaminated corks, at a very low sensory threshold of less than 3ppt, which is a very, very high standard, so we went ahead and ordered the corks. When the corks arrived, we again chose a random selection of corks from multiple bags, and were disappointed to find that the sensory evaluation suggested that 6% of the corks would be tainted.”
“We had a pretty rigorous testing regime. We'd select 60 corks and soak them in a neutral white wine for at least 24 house in individual containers. In the morning we'd pour a sample of each of these containers into a wine glass. We basically had this large, horseshoe lineup of 60 wine glasses around the island in the lab. We also had a couple of neutral control samples that were individual containers that did not have corks added to them. We'd go down the line and smell each sample and give it a score of 1, 2, or 3. One was normal, two questionable, and three definitely corked. Two of us went through twice each, and kept separate notes. On this particular day, both of us had one painfully obvious 3, three borderline 3's, 2-2's, and 54-1's. If you take 4 and divide it by 60, you get 6.67%. This was an unacceptable standard for us, and was surprising since the same exact procedure on the 'same' cork lots prior to purchase had yielded only a 2% chance, a full 300% difference. Not wanting to reject corks that were already branded with our logo based on some 'sniffing' tests, we sent the three borderline '3' corks down to ETS laboratory in St. Helena. They confirmed our findings and reported TCA levels of 2.2 ppt, 2.0 ppt, and 1.5ppt. We rejected the whole lot of corks, and boy did that ever unleash a firestorm.”
“The cork supply company quickly sent us a series of studies that ETS laboratory had conducted that suggested that our findings would only result in a 0.3% chance of cork taint, and that was as good as anyone could ever ask for, and we were “completely ridiculous” for rejecting such a pristine selection of corks. I was taken completely by surprise by these findings, and even began to doubt our own analysis until I read and reread the studies, especially the fine print. There were some assumptions made in the research that I just could not agree with.”
“The ETS study used a 'trained' panel of experts to evaluate cork taint and found that the human threshold of 'trained' testers was 6ppt. In other words, it wasn't possible for the human nose to detect levels of less than 6ppt. They then extrapolated that 'untrained' drinkers would have a detection threshold of no better than 10ppt. So, at a detection threshold of 10ppt, less than 0.3% of our corks would be tainted. This would seem to be a pretty low number.”
“The problem I had with all this research wasn't in the actual science, which relied on technology such as solid phase micro-extraction and gas chromatography and mass spec analysis. My problem was entirely with the assumptions. I had a major problem with their assumption that the human detection threshold was only 6ppt, when two individuals, only one of whom was an actual winemaker, had clearly picked out TCA tainted corks at levels as low as 1.5ppt. When I called the technical director at ETS, he told me there was 'no way' that humans could detect TCA at levels below 4ppt. When I pointed out that I had sent him three samples that I'd identified as being corked, and all three were below 4ppt, he sarcastically said I must be “Superman”. My wife loved that one, but it royally pissed me off.”
“I think consumers should feel ripped off by the cork industry. The cork industry is claiming that across all price points of wine, there is less than a 4% rate of taint. Well the problem with that is that it assumes that the threshold for the consumer is 10ppt. Clearly I've demonstrated that the threshold for some people is much lower than that. So using their own science, at my detection threshold, close to 20% of the wines I'm going to encounter are going to be corked, and that is an unacceptable standard for me. Actually, in our own experience, we find closer to 15% of wines we open at home are corked. The bottom line is, how can I ask my customers to adhere to a lower standard than I set for myself?”
Chenin has adds her own take on the whole thing:
“The other night we had guests over and I opened a nice bottle of Oregon Pinot and it was corked. I went back to the cellar and grabbed another bottle out of the same case and it too was corked. Two bottles of the exact same wine from the same case corked-I couldn't believe it. So I went down to the cellar again to grab another wine, a completely unrelated wine, and it was corked! Three corked bottles in a row!”
So, that's why we've bottled under screwcaps. We find great validity in the argument of corks being formal and traditional. We like that corks are able to be composted when they're done. We also think that they can sometimes be a pain in the ass to get out of the bottle. On the other hand, we recognize that unscrewing a wine at a nice restaurant is begging for a little more romance. And there is still an ongoing debate about the reductiveness and inertness of screwcaps. We'd like to think that someday corks will figure themselves out, but we are so personally offended by TCA tainted wines that we believe screwcaps to be the best choice for our wines.
The debate surely continues...