According to Sonoma winemaker Timothy Keller, "There's a compound called 2,4,6-trichloroanisol --You can call it TCA. It's easier-- that smells like moldy mop water, or wet cardboard. And when that's in the wine, the wine is ruined."
In addition, unavoidable variations mean one cork will breathe better than the next.
"And, so," explains Keller, "if you open up this bottle vs. this one, one will age faster, and one will age slower."
Screw caps are more reliable and convenient, but they have their own issues.
"Screw caps don't let enough oxygen in. So, we're kind of stuck with the traditional cork. So, I thought what if you made a screw cap that could breathe just like a cork, but then still have the reliability of a screw cap?"
Keller put four tiny holes on the top of his cap, one on the inside, and developed a special liner to go between them. The top and bottom are a metal foil with a special polymer filter between them. By moving the holes toward and away from the center, he can adjust the distance that air travels sideways through the filter, thus managing the oxygen.
"Right now" he laments, "we can manage it in the tank, we can manage it in the barrel, we can manage it while we're moving it. We can't manage it once the cork goes in the bottle."
When Keller proposed the idea to vintner Jim Morris, Morris was skeptical. Morris owns Alta Ridge Vineyards near Santa Rosa.
"I was skeptical. Even so, I think Tim's idea is unique, because it gives the winemaker much more control over what's happening inside the bottle. "
Better quality and fewer losses might appeal to the industry, but screw caps remain a tough sell to restaurants and consumers.
"Yeah," says Keller. "The customer still equates the screw cap with cheap wines."
Still, he has believers. His alma mater UC Davis just awarded him a $15,000 cash prize in the Big Bang competition for best new technology business plan.
------- Links -------
UCD Wino Tim Keller's Winemaking Blog
Big Bang Business Plan Competition Organized by MBA students of the Graduate School of Management at UC Davis.
Alta Ridge Vineyards participating in tests of the new caps.