The vast majority of corks are made from the bark of the oak tree Quercus suber, and come from the oak forests of Portugal. There are alternatives to the standard cork, however, the motives behind these alternatives being in some cases financial, and in some cases a quest for quality and consistency.

This is a fairly standard cork comprising a single piece of bark of about 24mm diameter. This is about 6mm wider than the internal diameter of the neck of the average wine bottle, which ensures a tight fit, provided the cork doesn’t dry out and contract.

This is an agglomerate cork, manufactured from tiny pieces of chopped cork, bound together by glue. The motive behind this closure is financial – the process allows for otherwise wasted pieces of oak bark to be made into something saleable. They are short, so more can be produced.

The Champagne cork is a little different. Slightly larger (31mm across, it is made from three pieces of cork sandwiched together. The mushroom shaped head protrudes from the top of the bottle, allowing the wine drinker to get a good grip on it when easing it out.

There are two main concerns about using natural cork to seal wine bottles. Firstly, fungal contamination of the cork results in 'corked' flavours, tainting of the wine producing a musty, cardboardy aroma and taste. With particular reference to agglomerate closures, many tasters detect a glue-like aroma or taste tainting the wine, a fault derived from the glue used to bond the tiny pieces of cork together. Also, the manufacturing process and use of many different pieces of bark in a single cork theoretically increases the risk of fungal contamination and the wine being corked. Because of the significant number of natural corks that are contaminated, resulting in corked wine (a generally accepted figure is about 5% of all bottles), many winemakers are opting for alternative methods of closure. There are two main methods, synthetic closures and screw caps.

This is a synthetic closure, of which there are quite a number of different brands on the market. Many go some way to imitating natural cork, in terms of colour at least, whereas some proudly display their synthetic nature by means of bold, impressive colours.

The debate about the efficacy of these methods of closure rages on, but my main concern is that there is not definitive proof as yet that wines bottled using synthetic closures age in the same way as those bottled using natural cork, a proven although admittedly flawed material. Hopefully research currently underway, performed by the Australian Wine Research Institute, will go some way towards demonstrating the effect of synthetic closures on the ageing of wine. One other concern about synthetic closures is the ruthless efficiency with which they strip the Teflon coating from more expensive models of corkscrew. I always recommend removing these corks using a simple butterfly model.

Finally, thescrewcap. This is an extremely efficient method of sealing a bottle of any consumable liquid, be it a carbonated drink, beer, salad dressing, orange juice, tomato sauce, mineral water or, frankly, wine. As with synthetic closures, however, there isn’t yet the necessary weight of evidence concerning long-term ageing necessary for important producers to switch from cork to Stelvin (one brand of screwcap). Stelvins are, however, currently used by some producers of quite fine wines intended for drinking in their youth, particularly New Zealand Sauvignon Blanc and Australian Riesling.


After bottling your wine and before inverting/turning your wine bottles upside down for storage you should leave your bottles in the upright position for a period of time prior to turning upside down or on their side for storage and aging. The argument for how long to wait is widely debated with opinions ranging from five minutes to 24 hours. We have read nothing that said you will hurt your wine by waiting 24 hours and there are plenty that are concerned that 5 minutes is not long enough. So bottom line, waiting before inverting is a must, and the longer you can wait, up to 24 hours, is the safest bet.

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