Straight cork (left) versus composite cork (right) closures.
Natural cork has been the wine closure of choice for centuries, but in the past few decades a debate over the benefits and shortcomings of alternative wine closures has flourished.
For the most part, the debate is over whether natural cork closures or screwcaps should be used to close wines. Most of the debate circles purely around perceptions, and there are a number of other types of closures that can be used, including composite cork, plastic and glass.
For most winemakers, though, there are three considerations to take into account when choosing a closure: cost, the type of product being bottled and marketing.
I spoke with City Winery winemaker David Lecomte to get his thoughts on this debate and learn how he chooses closures.
Lecomte says that he’s always believed, “There’s no bad closure; there is only the wrong closure applied to the wrong product.”
For Lecomte and City Winery, though, the only decision to be made is whether the wines should be closed with straight cork or composite cork, as the winery does not own a screw capper machine, which cost in the range of $15,000-20,000. Furthermore, Lecomte does not use plastic closures, as there is an unforgivably large disparity in sealing quality.
Cork wine closures are punched from cork oak tree bark.
Straight cork is made form the bark of cork oak trees, which is harvested about once every nine years. The bark is stripped away from the tree, and individual corks are either hand-punched or machine-punched from the bark (as pictured above).
After each straight cork is removed from the bark, the remaining bark is ground up into granules and compressed together to make composite cork.
Straight cork costs about $0.75-1.00 per closure, and composite cork costs about $0.07-0.18, depending on suppliers. (For the record, screwcaps cost roughly the same as composite corks.) Pricing and lead time for shipping are important for winemakers who must manage budgets and work on close timelines. As a result, closure cost is oftentimes a big deciding factor.
But the product’s profile is also an extremely important consideration. So when should a winemaker choose a straight cork over a composite cork, and vice versa?
“You shouldn’t choose a closure based on what you think. You should choose it based on your product,” says Lecomte. When deciding on which type of closure to use, Lecomte looks at a wine’s profile and its mouthfeel. “If the wine is all about the fruit, has a mellow mouthfeel, is ready to be drank and there is no point in aging it, there is no point in using a straight cork,” he says.
On the other hand, if a wine has the capacity to be aged for multiple years, a straight cork should be used, as a composite cork would limit the wine’s shelf life.
Straight corks provide the longest aging range, says Lecomte. Those used at City Winery have a lifetime of between 10-15 years.
Composite corks on the other hand “don’t seal forever,” says Lecomte. The $0.07 closure maintains its quality for about 1.5-2 years, while the $0.18 closure can last for up to 6-7 years.
Lecomte always runs tests on each shipment of corks to make sure that they are up to par.
Cork contains 2,4,6-trichloroanisole (TCA), a chemical compound that is the chief problem child when it comes to cork taint in wines. While all corks contain TCA, it’s a matter of keeping the average TCA content level and the standard deviation within check.
A wine that has been bottled with a cork that is contaminated with TCA is called a corked wine, identified by undesirable smells or tastes from the wine.
While some reports have stated that 5-7% of all wines are corked, Lecomte says that if closures are chosen properly, a winemaker should only experience 1-3% of his wines being tainted. Lecomte elaborated that 1% of that will be completely corked wines, while the remaining 1-2% will just be slightly spoiled.
For winemakers, slightly spoiled wines are a bigger problem, though, as the customer may just attribute the undesirable characteristics to poor winemaking instead of a tainted cork.
The best type of closure is one that seals well and has no TCA content. Lecomte says that 10 years ago, composite cork was the lowest quality of the two types of cork. But today, there is technology that can extract large amounts of the TCA content (and other volatile chemical compounds) from composite corks, making it a desirable choice today. This process lowers the average TCA content level and also minimizes the standard deviation. With composite corks now, there is practically no disparity between corks, giving all closures in a batch equal potential.
Lastly, marketing can be a consideration when choosing a closure type. Lecomte says that he previously worked with a winery in which the marketing department requested that 25% of its Sauvignon Blanc be closed with screwcaps, as the marketing team was opening up a new market. In this case, the wine marketers felt that consumers would be receptive to a closure that was trendy and easier to open. In another case, Bonny Doon Vineyard, a winery based out of Santa Cruz, California, embraces screwcaps as the closure of choice — a move that could be called a marketing decision.
Once a winemaker chooses which type of closure he would like to use, there are also considerations when choosing a specific model — quality, grade, length and supplier are just a few decisions to be made.
What are your thoughts on choosing wine closures? Let us know in the comments below.