Screwcaps and Bottle Aging?
I am writing this article as a follow up to support Marc’s infamous “Corks Versus Screw Caps” story. If you have not had the opportunity to read it yet, please do so. The article debuted on LocalWineEvents.com, and we received an overwhelming amount of responses, comments and questions pertaining to the post.
Many readers observed the need for educating wine stores and supermarkets about their corked wine return policies; some wondered why corkscrews were not accepting in the market; but the majority questioned the validity of bottle aging and screwcaps.
One such email, submitted by Emily Larkin, seemed to capture the essence of what most readers were asking, so I have included her comments below:
“What kind of research has been done on the use of screwcaps and the cellaring of wine. I feel confident producers of top Bordeaux’s or Barolo’s have not made the switch but it’s these wines in particular that intrigue me. I feel like I’ve been told that the relationship with cork and aging fine wine is significant. Cork being a relatively organic matter changes over time meaning small amounts of oxygen will come in contact with the wine and this occurrence in the cellar is a positive one. On the other hand if these sorts of wines were kept in cellar with screwcaps in a completely anaerobic environment how would they mature? Would a Stelvin closure produce the same aging effects in wines that we desire? Have you come across any long term research in the use of screwcaps?”
Emily (and many other readers) brought forth many valid questions – debatable ones at that.
In 1997, Plumpjack, a 10,000 case Napa winery that produces ultra-premium Cabernet Sauvignon ($100+ per bottle) bottled half of its 1997 Reserve Cabernet Sauvignon with screw caps. 10 years later, the wine fairs well; it exhibits a dense plum/purple color as well as mineral, black currant, floral, earth, and spicy new oak aromas and flavors.
In regards to white wine, the New Zealand Wine Seal Initiative group states, “wines in screwcap[s] do age and develop. They also retain primary fruit characteristics for longer, they retain freshness but they can have the developed character of a well aged wine”. This statement is backed by 30+ years of Riesling and Semillon screwcap packaging.
I have also heard that the university de Dijon bottled a 1966 Mercurey. My assumption is that it was a Pinot Noir from the Côte Chalonnaise region; unfortunately, I have not come across the findings of how the wine faired throughout the years, but my assumption is that the results are favorable; I don’t think they would talk about it had it failed the screwcap test :)
As for Bordeaux wines, 12,000 bottles of Les Tourelles de Longueville, the second wine of Paulliac chateau Pichon-Longueville, will be bottled with the closure. The announcement of this news happened January 2007.
Additionally, scientists from the Australian Wine Research Institute published a good study on closures in 2001. You might want to track down a copy for a good read.
As for bottle maturation, I will rely on a few reliable sources:
“… the quantities of oxygen that normally penetrate into the bottles are negligible if not zero. Oxygen is not the agent of normal bottle maturation.” J Ribéreau-Gayon et al (1976), “Traité d’Oneologie – Sciences et Techniques du Vin” Vol. 3.
“When a wine ages in the bottle, the oxidation – reduction potential decreases regularly until it reaches a minimum value, depending on how well the bottle is sealed. Reactions that take place in bottled wine do not require oxygen. “P Ribéreau-Gayon et al (2000), “Handbook of Enology – Vol.2 The Chemistry of Wine Stabilization and Treatments.
Additionally, According to Singleton, a UC Davis Professor, the chemical reactions responsible for bottle aging are not dependent on oxygen, implying that both a screw cap (and a synthetic cork) will not interfere with bottle aging. “My opinion is that bottle aging doesn’t occur unless there is a considerable protection from oxygen. So rather than saying slow contact is desirable, I believe that slow contact may not be desirable.”
As a side note, keep in mind that the Stelvin closure is not a new invention. La Bouchage Mecanique, a registered trademark of French manufacturer Pea-Pechiney, developed it in the late 1950’s. I think many have issues with the closer because they believe the gadget that has not gone through rigorous testing.
My two cents is that screwcaps are ideally suited for bottle maturation over a long timeframe, not just for current consumption. However, it will require many more years of research to prove its legitimacy before consumers and wineries make the jump.
If you disagree or simply want to remark, please feel free to leave a comment! This is an open discussion and I welcome the interaction.