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Clos de la Tech and the Quest for the Perfect Cork

Posted by CM Support
Dec 7, 2015 | Keywords: Clos de la Tech  Cork Taint  Pinot Noir  



It would not be an exaggeration to say that we are obsessed with the quality of our wine at Clos de la Tech.

We are meticulous in analyzing the soils and microclimates in our vineyards. We pay close attention to how the vines are growing right down to how much sunlight reaches each grape cluster, and we take up arms against pests and critters that threaten our crop.

We are fanatical about cleanliness. We monitor every stage, from fermentation to barrel aging to find the perfect moment to bottle our wine. We even have specific rules and protocols for the placement of the label on each bottle. 



With all that care and hard work, the last thing we can be casual about is the cork we choose. That innocent little cork could be harboring “cork taint.”

Cork taint is not just a criticism voiced by pretentious people who want to show off their advanced palates. Cork taint ruins wine, resulting in a musty, damp, moldy odor and taste in the wine. It’s estimated that about 2% to 5% of bottles are tainted with TCA to some degree, making it the second most common wine fault.

Cork taint is caused by the presence in the cork of 2, 4, 6-trichloroanisole, or TCA for short. This is what it looks like, chemically:



Very small amounts of this compound, on the order of nanograms, can be responsible for cork taint. While the human threshold for detecting TCA is measured in the single-digit parts per trillion, this can vary by several orders of magnitude depending on an individual's sensitivity.

TCA results from an interaction of certain industrial pollutants with microbial growth in the cork. To prevent cork taint, some wineries have chosen to seal their bottles with metal or plastic, but at Clos de la Tech, we are sticking with the classic cork, but adding our own level of scrutiny for sourcing them, decreasing our chances of receiving TCA-latent corks.

One of our key partners in avoiding TCA is Scott Labs. They do statistical analysis of their corks in St. Helena and with that analysis they can decide to accept or reject shipments of specific lots of corks from Portugal.  



We also do our own testing to evaluate different cork providers. For the testing, we use a light Chablis, which has little flavor and bouquet (so that the cork has the most influence). We seal individual corks in jars full of Chablis for no less than 12 hours and no more than 24 hours. We also seal a group of corks in a glass with lukewarm water for a backup test. When the time is up, we smell the wine in each individual jar (as well as the water in the glass) to determine which provider wins.

We then inform Scott Labs of our chosen provider and schedule our on-site sensorial analysis. After we determine which lots pass our sensorial analysis, we do a visual check to make our final decision on the exact lot. So far, we have been pleased with the Sterisun Corks because they receive a light hydrogen peroxide and water wash followed by neutralizing rinses. They are then dried to a moisture level between five and eight percent.


The Clos de la Tech cork-test set-up.


As always, we make every effort to ensure every bottle of Clos de la Tech Pinot Noir is as perfect as possible. Salud!