Readers uncork over screw caps

My recent columns on the growing acceptance of Stelvin (screw cap) closures for both white and red wines brought a flood of interesting reader mail.

I do appreciate the thoughtfulness that goes into many of these communications. Here are some of the most interesting comments. Some readers, I learned, reject screw caps on environmental grounds:

"I object to screw caps," wrote David S. "A whole region of Portugal depends on cork oak trees for the livelihood of the people that live there. If they can't make money by harvesting cork, they will likely cut down the trees and develop their beautiful oak savannah landscape into some economic usage that wrecks the feel of the place. Yay for cork in wine bottles!"

"In the past I would have agreed with your article on screw caps," wrote Kenneth B. "I thought corks were retained for their snob appeal. However, an article in National Wildlife magazine about a year ago explained how important the cork trees are to areas of Spain. The groves are important for wildlife and their production of cork prevents them from being bulldozed down and developed for condos or manufacturing. The article said the biggest threat came from the plastic type corks."

While I have not read the National Wildlife story, this concern about saving the cork forests seems to be the latest volley in the escalating public relations assault from the cork producers. Honestly, these arguments don't pass the sniff test. What cork producers need to do is improve their product so that bad corks do not ruin perfectly good wine. It is not the responsibility of wineries to fund the preservation of forests by purchasing faulty corks! As I wrote, wineries that use natural cork are still very much in the majority, and likely to remain so. And to make the record perfectly clear, I do not like or endorse plastic corks.

Onward. Some readers, it seems, don't trust screw caps:

"I am a huge fan of New Zealand sauvignon blancs," writes Julie O."Someone recently told me to stay away from screw tops because they put ether (I think) in them to help preserve them. I think he is thinking of the older cheaper wines that had screw tops. Your thoughts?"

No worries, Julie. I can't find any reference to ether or anything remotely like it in conjunction with the manufacture of screw caps. Wines are bottled with small amounts of SO2 (as explained later in the column); that may be what your friend was thinking of.

Here's a different anti-screw-cap gripe from a reader in Canada:

"No argument about the quality of screw-top wines but ... in order to drink the wine it is necessary to be able to open the bottle. Having just returned from Australia, I consumed plenty of wines with screw tops. Almost without exception they were difficult, if not impossible, to open. There is no serrated line to cut prior to turning, and turning by hand takes more strength than either my wife or I have. We have now resorted to using a pair of channel locks [pliers] to open the top. Greatly needed are either an easier opening top or a device to replace a corkscrew."

Good news. There are corkscrews made with a special fitting for wrenching off screw caps. Check with your local wine shop and if they do not have one in stock they should be able to order it for you.

"I'm not sure how something as nefarious as the oft-touted metal and plastic-based screw caps can be considered a positive for the wine industry," grumps Terry G. "These 'popular' caps will add extra, non-biodegradable substance to our over-flowing landfills. Stick with cork; it's fast growing, sustainable and biodegradable. With sulfites, pesticides and migrant worker labor being troublesome issues for the wine industry, would it be too much to ask to keep something that makes as much sense as a cork for our wine bottles?"

I will do further research on the environmental questions raised by Terry, but the main point I was making is that cork taint is a very real problem that affects a significant amount of wine. What do you suppose is the economic and environmental impact of all that wasted product?

"Another article on corks versus screw caps," writes Mark N., "and yet the central issue never seems to be fully addressed: is atmospheric oxygen involved in the aging process of wine? If that question is fully answered (and assuming the answer is 'yes') then it becomes a simple issue for both producer and consumer. Do I expect this wine to have aging potential? Then only buy it if it has a cork stopper. Do I care if New Zealand sauvignon blancs have screw caps? No."

Mark, I don't think anyone would argue that corks are permeable, and allow some gentle oxidation to occur. But you are mistaken when you say that screw caps do not. There are screw caps that are designed to allow bottles to breathe, and wineries can choose the desired level of porosity. Aging wines under screw caps has been (and is being) thoroughly researched. Winemaker James Mantone of Syncline Wine Cellars sent me this comment on his aging and bottling of wines under screw caps:

"I just read your new article on Stelvin closures and white wines," he writes, "and this is obviously a subject dear to me as we have recently gone 'cork free' at Syncline Wine Cellars. I have struggled with the idea of using such an anaerobic seal on wine for a number of years and began my experiments cautiously. The first wines bottled under screw cap were rosé and viognier. As we gained experience we have learned to deal with the potential anaerobic/reductive environment by modifying our winemaking techniques. Interestingly, this has led us back to some 'traditional' techniques: extended lees aging, lees add-backs, bigger barrels, older barrels.

"In addition, we have noticed quite an effect on our SO2 levels. Under cork we may have gone in the bottle with 25-35 ppm SO2. Six months later it was 15 ppm, and one year later it was 8-12 ppm. Under screw cap the SO2 levels at six and 12 months remain the same as at bottling! This means that we are now going into the bottle with lower SO2 levels than previously and still maintaining a higher level of protection for aging.

"In relation to red wines and screw caps, it took a bit more convincing before I was ready to make the move. Then I was exposed to 15-year-old riesling under screw cap that had all the petrol and waxy character you would expect from an older riesling, yet it still tasted of lime and apricot flavors. This led me to believe that two processes are occurring in bottle: maturation and oxidation.

"Maturation is the development of the mature flavors and seems to occur even in an anaerobic condition, while oxidation is the degradation of the fruit, secondary flavors, and stability of the wine. I am therefore completely in support of screw caps and the new vino-lock glass for white and red wines."

How to find recommended wines

Unless noted, all Wine Adviser recommendations are currently available, though vintages may sometimes differ. All wine shops and most groceries have a wine specialist on staff. Show them this column, and if they do not have the wine in stock, they can order it for you from the local distributor (noted in parentheses).

Paul Gregutt's column appears weekly in the Wine section. He can be reached by e-mail at wine@seattletimes.com.