UC Davis students uncork an award-winning wine cap

Keller's design offers the prospect of a cap that eliminates the worry about taint while still letting in oxygen.

His team's patent-pending design – which so far lacks a catchy name – is a 5-cent disc that fits beneath a screw cap. Made from alternating layers of polyethylene – the same material used to make sandwich bags – and perforated aluminum or tin, it can be fine-tuned to match the oxygen demands of different varietals.

"Pinot noir needs a little, cabernet sauvignon needs a lot," Keller said.

LINK.

This sounds like BS to me. That last statement is something I have never heard before. Has anyone ever heard that or, more importantly, have any info on studies that supprt such a statement?

Mike

Here is a little more on the people and thinking behind this new closure.

The high-tech wine cap was developed by MBA student Tim Keller, a UC Davis viticulture and enology alumnus who worked for 10 years as a winemaker in Sonoma and Napa counties before enrolling in the Graduate School of Management, and his teammates, Kevin Chartrand and Diana Mejia. Chartrand, a fellow MBA candidate with an undergraduate degree in materials science, worked as a thin-film expert at IBM. Mejia, a former engineer for Anheuser-Busch, is earning a master's degree in food engineering at UC Davis.

Their team, Advanced Enological Closures, set out to design a better bottle cap because cork taint, a byproduct of a fungus that infects cork and makes wine smell like moldy mop water or sweaty gym socks, now contaminates the corks of an estimated one in 20 wine bottles on store shelves, ruining billions of dollars of wine annually. Although synthetic corks have been developed in response to the problem, they allow too much oxygen into the bottle, according to Keller. Overly oxidized wine has a shorter shelf life and can develop a fingernail-polish odor. Screw caps -- another alternative to bark corks -- are a viable option for wine white, but do not allow in enough oxygen for fine red wines, Keller said. Without enough oxygen to draw on, red wines start to smell like burned rubber or matchsticks as they age. LINK

Mike

I'm so dumb. To get the answer I should have just searched under Tyson Stelzer.

The question of the ageing rate of wines in screw cap has been a hot topic of late. It is my belief that the rate at which mature notes (or "characters," as we say Down Under) develop in screw-capped wines is in fact absolutely no different to that under traditional closures. This is evidenced by the fact that wines under screw cap age at a similar rate to those with the very best corks. For a wine under an average cork, however, oxidation effects give the impression of accelerated ageing, which has led to the notion that wines mature slower under screw caps. I believe that the absence of oxidized characters in screw-capped wines gives the mistaken impression of slower ageing.

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More criticism has been levelled at screw caps by the media in relation to reductive characters than any other fault. I encourage you to view these accusations objectively and judge for yourself. If there is a causal link between screw caps and reductive characters, as some claim, then we should be tasting more reductive wines under screw cap than under cork.

Check it out for yourself, but my experience, and that of hundreds of experts with whom I have had this conversation, is quite the opposite. In my own tastings in recent years, comprising thousands of predominantly Australian and New Zealand wines, I have encountered more reductive wines under cork than I have under screw cap.

The managing director of the AWRI, Professor Sakkie Pretorius, commented recently that "The idea that there is a high incidence of post-bottling reduction in wines sealed with screw caps is a false premise. With Australian wines, where the AWRI has particular expertise, this is demonstrably not the case…. Our position, which we believe is undeniable, remains that the propensity of a wine to develop 'reductive' aromas post-bottling is a function of the wine, and that post-bottling reduction is not the 'fault' of the closure but may be exacerbated by the closure if the wine has a propensity for such aromas to develop."

"In his Screw Cap Symposium presentation, Peter Godden discussed data from one of our AWRI Advanced Wine Assessment Courses which indicates a higher incidence of reduction in wines sealed with cork compared to wines sealed with screw caps. Two subsequent courses have provided similar data." LINK

Mike

Further scientific research is definitely required to fully understand the science of bottle aging and the role that the many different enclosures now available have on a wine’s evolution during bottle aging. IMHO I think it is pretty clear that aging wine in a bottle takes place under micro-oxygenation (we’re taking very small amounts of oxygen ingress). However, the big issue is just how much oxygen ingress through the enclosure is required (and is the timing of the oxygen ingress important) for a wine to age correctly in the bottle without oxidation or reduction problems. An age worthy wine can actually benefit from both a “little” oxidation and reduction.
Obviously this will depend upon the grape varieties and wine making techniques and practices used to produce the wine. In the case of color development in age worthy wines, generally, white grape varieties benefit from enclosures which have a “tight” seal, and red grape varieties benefit from enclosures that allow a “little” oxygen ingress (some red grape varieties will benefit from a little more or less oxygen ingress depending upon how much of the component responsible for color is present in the wine and other factors).

Salute

Further scientific research is definitely required to fully understand the science of bottle aging and the role that the many different enclosures now available have on a wine’s evolution during bottle aging.

That is very much the impression I get too. For me, one of the really interesting aspects of being able control oxygen ingres using different screwcap disks is that we now actually have a chance of understanding the role of oxygen in in-bottle aging. It is a hopeless situation trying to do this with corks as there is too much natural variation.

Further scientific research is definitely required to fully understand the science of bottle aging and the role that the many different enclosures now available have on a wine’s evolution during bottle aging.

That is very much the impression I get too. For me, one of the really interesting aspects of being able control oxygen ingres using different screwcap disks is that we now actually have a chance of understanding the role of oxygen in in-bottle aging. It is a hopeless situation trying to do this with corks as there is too much natural variation.

Sounds like a bunch of PhD dissertations in the making!

I agree, though. If this does work out it will add a lot to our knowledge of how wines age.