The primary task of any wine closure is, obviously, to protect the contents inside the bottle as well as preventing the stuff from leakage prior to the grand moment where the bottle is opened and drinking joy commences. However, after some practical research of late it is evident that the closure’s role supersedes the merely functional, in fact having a profound effect on the taste of the wine.

This is obviously known to most winemakers – or should be. But as a keen and motivated consumer it is enlightening to experience the difference a closure makes. Wineries jump to communicate the fact that their wines are aged in new or third fill barrels, for example, as this creates expectation in the mind of the consumer. Yet little is said on the nature of the closure with which the wine has been shut, despite the fact of this object’s influence on the product’s final personality being evident and rather profound.

I had heard much talk about the impact different cork closures have on bottled wine but had never been allowed into the rarefied surrounds where experts assess such influences. And even if I were, my limited amateur sensorial abilities would surely not allow me to distinguish differential aspects resulting from something so apparently negligible as the structure of a cork closure. 

An experimental bottling of Chamonix Estate Chardonnay 2021 under three different closures recently allowed me to join winemaker Neil Bruwer and CEO Stefan van Rooyen in assessing possible degrees of variance. A cork-supplier had provided three corks: composite, twin-top (composite centre between two natural cork discs) and a natural cork. Same vineyard, same barrel aging, same wine. Aged in bottle for one year, but under three diversely different cork stoppers.

Chamonix’s blue-blooded, classically complex Chardonnay was ideal for providing evidence of the diverse effects of the three cork closures, so much so that even my non-winemaker palate was easily able to detect the differences.

From the outset it must be said that all three wines displayed the characteristic distinctive trait of Chamonix Chardonnay. This is a comforting density on the palate. A satisfying mouth-filling presence with notes of quince and sun-dried lemon-peel, a crack of mace elevated by glowing instead of brisk acidity. So, the effect of the cork closure was not suppressing site and place, just allowing it to be experienced with tweaked nuances.

The three closures were composite cork, twin-top and natural cork.

Composite corks are cork granules that have been moulded into a stopper with a neutral binder. And the Chardonnay closed under this model was reticent and apprehensive to yet offer the full array of white fruit and nuttiness for which Chamonix Chardonnay is known.

But it must be said, the longer the wine under composite cork spent in the glass, the more it opened-up to express a more familiar sense of what it can offer.

The twin-top is a good-looking cork with its natural cork discs set on the top and bottom between a fillet of composite. Here the Chardonnay was presenting its more familiar Chamonix guise. The wine had a broader and sunnier presence on the nose, Chamonix’s supple palate-weight now more discernible with the white fruits and green almond coming to the fore.

The final wine was closed under natural cork, i.e. stoppers drawn from the bark in solid cylindrical cork units. Initially the impression here was similar to that found in the Chamonix wines closed under twin top, although after a few minutes of rigorous assessment all three tasters agreed that this wine was the most complete in its sensorial offerings. There was a finely tuned balance between acidity and fruit, as well as an impression of a wine polished in terms of flavour-profiles and texture.

My take was that none of the closures had after a year in the bottle-neck led me to experience that any of the wines are better. A class product remains a class product, and we were assessing experimentation with a fine wine. But discernible differentiation? Absolutely. If I were in the game of the close scrutinising of wine and rewarding them with points out of a hundred there is sure as hell enough going on in the differing closure-effect to make the choice of closure an aspect worth mentioning. Or at least, taking note of. Because it’s real.