Individual tastes differ: About 10% of drinkers prefer corked wines

Quality control at Amorim's cork factory in Portugal

The cork industry is always sending me interesting data on how bad screwcaps are for wine. Recently I got an even more interesting study: that some consumers prefer corked wines.

Granted, this study, published in Food Quality and Preference journal,
was commissioned by the cork industry. But I don't doubt it.***(see update below) Peoples' tastes differ, dramatically so. Do you like your neighbors' music? If so, you're lucky, or you live next to radio host Dennis The Menace.

Update: This study was paid for by Hanzell Vineyards, not the cork industry. More details at bottom of post.

What the study was trying to establish is the threshold of TCA, the chemical that causes "cork taint,"* that would cause consumers to notice and reject the wine. A 1995 study estimated that tainted corks cost the wine industry $10 billion, so a data point like that is worth having.

* That's "cork deliciousness" for you 10-percenters

In an irony that New Zealand winemakers will smile at, the scientists used New Zealand Chardonnay bottled under screwcap and they added TCA dissolved in ethanol at different concentrations.

In one experiment, the scientists* were surprised to learn that no matter how much TCA they added, more than 10% of consumers would not reject the wine. They posited that perhaps the consumers' noses had become accustomed to TCA. So they designed a second experiment to check the finding.

* John Prescott from James Cook University in Cairns, Australia; Leslie Norris from Flavor Sense in San Rafael, California; and Madeleine Kunst and Sandra Kim from University of Otago, New Zealand

In the second experiment, 30 consumers were given pairs of wine, one with and one without TCA. They were given just four wines a day, for two days, and rinsed their mouths before and after each sample pair.

The study concluded that 3.7 parts per trillion of TCA is the critical tipping point where more consumers will reject it than not. That's interesting if you're a chemist, but it means nothing to me.

People preferring no TCA in wine never reaches 100%

Here's the interesting point: one sample wine had 32 ppt of TCA added -- nearly 9 times the threshold amount, enough to send most sommeliers gagging out the back door of a restaurant.

And 10% of consumers not only didn't reject that wine -- they preferred it.

If you think about it, 10% of consumers is a huge market. Maybe some savvy wine company can come up with a new niche product: Corkin' Cabernet, now with extra TCA!

About the funding for this TCA study: Two of the scientists reached out to me to say the cork industry did not fund it. 

Here's what Leslie Norris, president of Flavor Sense, told me by email:

The  Consumer Rejection threshold study was NOT sponsored by the cork industry, but arose from a "real world problem" at Hanzell Vineyards.  The Wine Spectator wrote an article "exposing" that Hanzell had a TCA problem in their wines.  Hanzell paid ETS to measure the amounts of TCA actually in their wines.  Hanzell then hired FlavorSense to intepret the analytical data.  With Hanzell, we defined the objective of the study as: "at what level of TCA can Hanzell no longer sell the wine?"  FlavorSense and John Prescott came up with a protocol to determine the consumer rejection threshold (CRT), and we dosed the wines at a range of concentrations.  Based on the results of the CRT and the fact that Hanzell's ppm of TCA were under the CRT,  we recommended that Hanzell could offer the wines for sale to the public. They did and sold out their entire stock for that year!  Still one of my prouder moments!  Good question, good science!

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