A question about cork taint - cork batches

[Houndsong]

So I noticed that the 1990 Semeillan Mazeau I just purchased came in two sequentially numbered batches per the label: bottles 2,6xx and 12,xxx, the numbers in each series being very close sequentially. I opened one of the 2,6xx bottles and it's corked. That had me worried. I opened one of the 12,xxx bottles and it's fine (Very Good Indeed at least). I'm wondering though if cork taint could affect a whole bottling run if the corks were sourced from the same bad batch. And I'm wondering, what makes a bad batch and what makes a bad cork? Not the chemical of course, but would all the corks sourced from the same sheet of bark (or the underlayer of bark)be bad if one is?

Guess I could google it, but has anyone had several corked wines from a single lot of the same wine?

[DavidG]

Maybe. All of above is possible.

I tend to buy in 2s to 6s of most wines. Only twice that I recall have I had 2 corked bottles from the same batch. Many times I've had only one corked wine from a batch.

[dstgolf]

Hound,

If cork taint is originating truly from a bad batch of corks it's unusual that a single lot of wine would have corks all sourced from the same involved tree. These are bought in huge batches by the winery from the cork producer and mixed and matched accounting for an inconsistent # of bottles in a case being affected. There is however a systemic source of taint which can be endemic to the winery and can occur at many stages and be hidden in different sites within the winery itself. I was looking this up a while ago and credit to wikipedia for the following. A winery can be plagued and driven crazy to localize the source as it can effect an entire production!

"Systemic TCA
Systemic TCA tainting occurs when TCA has infiltrated a winery via means other than cork and can affect the entire production of wine instead of just a few bottles. This occurs when wine barrels, drain pipes, wooden beams in the cellars, or rubber hoses are tainted by TCA. Sometimes entire cellars have to be rebuilt in order to extinguish all potential systemic TCA culprits. Rubber hoses or gaskets have a high affinity for TCA and therefore concentrate TCA from the atmosphere. Wine or water that subsequently passes through infected hoses can become tainted with TCA. Another possible means of TCA contamination is through the use of Bentonite, a clay preparation used in treating wine for heat stability. Bentonite has a high affinity for TCA and will absorb TCA and related chemicals in the atmosphere. If an open bag of Bentonite is stored in an environment with a high (1-2 ng/g or ppb) TCA concentration, this TCA will be absorbed in the Bentonite and transferred to the wine lot to which the Bentonite is added.
It is notable that this systemic TCA will often impart a trace (1-2 ng/L or ppt) to the wine, which itself is not detected by most consumers. However, with this high baseline level of TCA in bottled wine, even the additional contribution of a relatively clean cork can elevate the TCA level in the wine above threshold levels (4-6 ng/L or ppt), rendering the wine "corked."
The primary chemical precursor to TCA is TCP (2,4,6-Trichlorophenol), an anti-microbial agent used in processing wood. Molds (and some suspect bacteria such as Streptomyces[3]) are able to de-toxify TCP by methylating the -OH to -OCH3, which is not toxic. Chlorinated phenols can form chemically when hypochlorous acid (HOCl-, one of the active forms of chlorine) or chlorine radicals come in contact with wood (untreated, such as barrels or pallets.) The use of chlorine or other halogen-based sanitizing agents is being phased out of the wine industry in favor of peroxide or peracetic acid preparations. Chlorine dioxide has not been shown to produce these spontaneous chlorophenols. Wine Spectator has reported that such California wineries as Pillar Rock Vineyard, Beaulieu Vineyard, E & J Gallo Winery and Chateau Montelena have had trouble with Systemic TCA.[4]
[edit]"

[DavidG]

Exactly right, Danny. There was also a systemic TCA problem at Ducru Beaucaillou in the (late?) 1980s.

[dstgolf]

There were many wineries through Bordeaux that had issues with taint stemming from a practice of using chlorine to clean down everything in the wine making area. Rafters,hoses,pumps,crushers were all becoming infected with taint. Some were publicized but this has been another French secret that they've wanted to bury. Ducru had the problem from 88-90 in a well published way. Chateau Canon was plagued from 92-96 and when Chanel bought Canon they spent over $500 K to fix the problem. Latour was hit in 94 with counts more than twice the levels that Ducru had in the late 80's. This is not an isolated problem and most go unpublished.

I remember after the Bealieu Vineyards problem was publicized in the Spectator in the 90's I had an experience with Simi Cab Reserve. The 96 was beautiful so when the 97's came out so highly touted I bought a case. I remember well uncorking the first 4 bottles and all were badly corked. I felt without question this must be a case of systemic taint. I contacted the winery to ask if they new of a problem. There was a flat denial and they became accusatory. From their discussions I new this was going nowhere and all I was trying to do was inform them of a potential problem and did they get their backs up. Took the entire case back to the LCBO and have never had a Simi product since. Amazing how a little bad PR can turn someone off for ever! Some people don't get it!

[Claudius2]

David
Exactly.
The cause was found to be some chemical used in the chais.
I think it was paint or some sealant used, which was no initially identified and affected vintages ffrom about 86 to 90.