Seals of approval



Roman Kauls is a sales assistant at our Warehouse Shop, and an ardent fan of finely-constructed German Rieslings. For our latest blog entry he considers a trio of solutions for a perennial enquiry, namely how best to keep wine in the bottle

One question that comes up time and again at our Warehouse Shop is this: “Which method is the best to keep the wine in the bottle?” Contemporary research and development has enabled us to utilise a variety of different closures to achieve this, but do all of them provide the same quality? Let us consider some of the most common ways to preserve wine – and their efficacy:


The classic cork is comprised of bark tissue and is harvested from quercus suber, more commonly known as cork oak. The cork as we know it has some fantastic attributes that make it the most commonly-used closure, namely that it is impermeable, elastic, and breathable. Due to its cellular structure it forms a perfect seal to the bottle; however, as cork is a natural product it also contains some weaknesses – cork taint and oxidation are the main issues faced by both consumers and producers, and on average one in 20 bottles are affected by it.


A screwcap does literally as the name implies, screwing the cap tight onto the bottle. A layer of soft plastic or rubber is placed where the aluminium cap meets the bottle neck to ensure the closure is tight. In Australia and New Zealand in particular this type of wine preservation has overtaken the classic cork, but what exactly are the advantages? It is, of course, easier to open and re-close, while production costs are lower than those of natural-grown cork. Recent studies have shown that ageing is also possible with the screwcap method. However, the cheaper versions don’t allow the wine to breathe, and are mostly made from non-renewable resources. While you might think that bottles under screwcap would be free of so-called “cork taint”, they can still suffer at the hands of this strain of bacteria (2,4,6-trichloroanisole) although the risk is markedly reduced.

Vino-Seal or Vinolok

Let’s contemplate a rather more unique way of wine preservation: the glass cork. This unusual design is probably the most aesthetic way of closure and, due to a rubber ring between the stopper and bottle neck, it bears similar characteristics to the screw cap. The main disadvantage is a question of cost: not only is the production process dear but most bottling plants can’t accommodate this style of closure, leading to even higher manual labour fees. Its true benefit is a more benevolent one, as the Vino-Seal (or Vinolok – depending on the manufacturer) is 100 percent recyclable.

So, what is the best means of sealing in one’s nectar? The simple but straightforward answer is none of the above. Bear in mind there are many other solutions such as alternative packaging and other closures – including the Zork and synthetic cork. In my mind the Screw-Cork (officially known as Helix) offers the most promising future, especially with the continuing gains in research and development. The Vino-Seal is undoubtedly the sleekest and most unique. Yet there is a palpable sense of ceremony with a traditional cork, from the moment it is pierced by the corkscrew to that unmistakable ‘pop’ when the wine is uncovered. For this alone I’m happy to take a gamble on the organic ups and downs of the humble cork.