As many of you know, I review Washington and Idaho wines for Wine Enthusiast magazine. Throughout the year, I keep a tabulation of wines that use natural cork closures as well as various types of alternative closures. I also keep track of wines that appear to have cork taint.

Below is a summary of these data for 2017. In short, about 77% of wines sampled used natural cork; 23% used some type of alternative closure. The majority of alternative closures were screwcap (12.2%) followed by DIAM (8.56%), a cork composite that is said to be cork taint free. Nomacorc – a synthetic cork – and glass stoppers meanwhile made up a smaller percentage of the wines sampled.

Of the wines that used natural cork, 3.59% appeared to have cork taint (I say appeared because the wines were not sent in to a laboratory for confirmation). The lowest percentage I’ve ever seen is 3% (2010); the highest is a bit above 6% (2016). The average price of the corked wines in 2017 was just over $36.

Cork taint is most commonly caused by 2,4,6-trichloroanisole (TCA). It typically presents itself as a musty basement aroma and/or flavor that can negatively affect the sensory enjoyment of a wine. The cork closure is most often the cause, though there can be other causes. The most obvious cases of cork taint are quite easy to detect if you know what you’re looking for. In the least obvious cases, it might just mute the aromas and flavors and be quite difficult if not impossible to detect.

For my purposes, I consider a wine to be corked if I smell what appears to be cork taint either on the bottom of the cork (yes, I smell every cork I pull) or on the wine. While it is possible to smell cork taint on the cork and not have it impact the wine, which may lead to some false positives, it’s not a risk I’m willing to take when reviewing wines. So, if a second bottle of the same wine was submitted (as it most often is largely due to the issue of cork taint), I put that bottle in the queue.

It is important to note that in almost all cases, I am tasting young, newly released wines. As cork taint can become more prominent/perceptible over time, my sense is that the percentage that I report here could be on the low end as there are most likely false negatives as well. That is to say, if this exact same group of bottles was sampled 10 years later, the incidence of cork taint might well be higher.

To try to account for this, I retaste each wine that I sample 24 hours after originally tasting it to look for latent cork taint. Additionally, I retaste a subset of wines over a more extended period of time to evaluate ageability. There were several instances this year, as in years past, where I discovered a wine to be corked on the second, third or even the fourth day. Presumably if I resampled every wine this way, I would pick up more corked wines as well.

It is important to note that there are very large individual differences in sensitivity to cork taint, with the most sensitive group of people said to be 200 times more sensitive than the least sensitive group of people. Additionally, individual sensitivity varies as well, with some who are able to smell TCA at less than 1ng/L on certain days not able to smell it at 6ng/L on other days.

I have seen the variability in sensitivity in my own tasting group. There are a couple of people in the group who are quite sensitive to cork taint and a couple of people who are quite insensitive to it, by their own admission, both backed up by our experiences in the group. The rest are somewhere in the middle (I should note that these are all trade professionals). I’ve seen it in my own home where, my wife, who is more sensitive to cork taint than I am, has on occasion pointed out that a bottle is tainted that I have missed.

This means that, even if you know what to look for, you might get a corked bottle and not know it. To this point, it’s not uncommon for me to find corked bottles of wine being poured at trade tastings, even if they’ve been proofed (I found two at an event recently).

As I have written about cork taint both in this space and on the Washington Wine Report Facebook page numerous times over the years (okay, maybe ‘numerous’ is an understatement), my sense is that many believe that perhaps I am just star crossed when it comes to cork taint. However, I believe that the incidence of TCA tainted wines I see is no greater or less than the incidence of tainted wines you see, assuming we’re drinking roughly the same selection of wines. I just might be slightly more sensitive to it than some. I also open a lot of bottles for review each year, and this has certainly helped me become more attuned to it.

Why do I care so much about cork taint? Two reasons. First, because as a consumer, it is extremely disappointing to have a corked bottle. I’ve had corked bottles on birthdays, anniversaries, and other big events. When I am opening up that special bottle of wine that I have saved for (insert the number of years here), virtually all I am thinking about is whether or not the wine will be corked because I’ve had so many corked bottles. Yes, a winery will most likely give you a replacement bottle if you ask for it, but probably not the same vintage. Additionally, the moment is gone.

Second, as a critic, I look at cork taint the way that I believe every winemaker should – as an existential threat. Every bottle of wine that someone purchases based on my recommendation that turns out to be corked hurts my reputation, because the likelihood of the person recognizing the fault is often not very high. Most will just think it’s a bad bottle of wine and that my review was inaccurate.

Many winemakers know that cork taint is an issue in the industry but, curiously, some seem to think that it’s not a significant problem for them personally or believe that they are taking sufficient steps to minimize the it. I once had a winemaker tell me that it was “impossible” that I had a corked bottle of wine from them, even though they were not using any type of taint free cork. This tells me understanding of cork taint in the industry needs to improve.

Closure choice is very much an individual decision for wineries, and I accept that. I don’t think that there necessarily is any perfect closure. I also understand the reluctance to use new products that don’t necessarily have a long history behind them, especially if you are making wines that are intended to be aged for extended periods. However, I think accepting the status quo when it comes to natural cork (buying more expensive corks, doing sensory testing of bales, sending a selection of corks off to a laboratory for analysis, etc.) is not enough.

If you’re a winemaker, unless you’re making wine from a product that is claimed to be TCA free – such as DIAM corks, screwcap, Nomacorc, glass closure or potentially the new technology that allows each natural cork to be individually test for TCA – cork taint is an issue for you. It’s just a question of how large of an issue, and the answer to that is you might not know. Personally, I would find that unsettling. I do hope that recent advancements in individually testing corks for TCA might lead to significant improvements. Time will tell.

I’ll close by telling one of my favorite stories about cork taint. Several years back I was tasting wine with a producer, and we were talking about the issue of cork taint. He said, “Well we just had our spring release recently, we opened up a lot of wine, and we didn’t have any corked bottles. So I think we’re doing really well.” I leaned down and smelled the wine that he had just poured into my glass and said, charitably, “Is this wine corked?”



# Natural cork

# Corked

Avg $ Corked

# Screw



# Noma


# Glass



(75.25% red;

21.54% white;

3.21% rosé)



(84.09% red;

11.36% white; 4.55% rosé)


Max: $95

Min: $10

Median: $34






* The vast majority of the wines referenced were from Washington but the sample does include a small number of Idaho and American designated wines.

** Of technical corks, only DIAM corks were tracked separately. All others were included in the natural cork bucket.

Note: The following line – “In 2017, none of the technical corks showed signs of cork taint (Note: This has not always been the case in previous years).” – was removed from ** above as I did not understand that technical corks include 1+1 corks in addition to agglomerative corks. I had a number of 1+1 corks that showed signs for cork taint in 2017.