Taber on cork
17 Nov 2007 by Jancis Robinson

This is a longer version of an article also published in the Financial Times.

In the 1990s I went to take a look at Amorim in Portugal, the world’s pre-eminent cork supplier. On the way to one of their cork processing plants my host anxiously discussed the weather reports in Europe’s wine regions. Spring frosts and unsettled weather in June when the vines flower can seriously reduce the number of grapes, thereby having a direct effect on the number of corks needed the following year. Wine bottle stoppers account for 70 per cent of the value of cork producers’ sales. The cork industry and the wine business are symbiotically linked – which is why it is so extraordinary that there has traditionally been such a gulf between them. 

At a restaurant later that day, my host clearly had remarkably little notion of what to order from the wine list. Unlike wine glass manufacturers and designers, cork producers have rarely been seen on the international wine scene. But most extraordinarily of all, cork producers spent almost two decades in denial about a cork scourge that fatally tainted a substantial proportion of the wine it stoppered. 

The offending compound TCA, so strong that one teaspoon would be enough to contaminate Lake Constance, was first identified by a Swiss scientist in 1981. Hans Tanner discovered that powerful concentrations of this chlorine-related compound were present in all the undrinkably musty, mouldy-smelling wines rejected as being ‘corked’, and in his very first paper on the subject suggested that this could well be due to the chlorine then widely used by cork manufacturers to bleach corks and make them look higher quality. This indeed proved to be the case but the cork industry refused to believe it until 2000 when a young Frenchman working in a private lab in the Napa Valley came up with a reliable way of measuring TCA levels in corks, thereby proving that at least 30 per cent of those being shipped to American wine producers then were tainted with perceptible levels of TCA. 

George M Taber, author of The Judgment of Paris, the highly regarded book about the famous 1976 France v California taste-off, has written the tale of the wine stopper battle in the well paced To Cork or Not To Cork recently published in the US. There are none of the “he gazed out over a wintry sky” embellishments that can blight these supposedly non fictional accounts, just the surprisingly gripping story of the conflict between increasingly frustrated wine producers, an obdurate cork industry, some truly obfuscating public relations activity and supporters of various alternative bottle stoppers. Such is the intensity of the holy war between screwcap and natural cork factions that, as Taber chronicles, it has precipitated the reignation of the British wine trade weekly’s editor, some absurd claims concerning the effect of screwcap purchase on the Iberian eagle and even an intervention from Prince Charles arguing the case for natural corks on environmental grounds although he, as Taber points out, “may never personally have pulled a cork in his life”. 

The book is admirably thorough, chronicling the dot.com-like rise of the plastic SupremeCorq (British supermarkets played a key role) and the (largely French) screwcap’s progress to its current position over the bottlenecks of 95 per cent of all New Zealand wine and over 50 per cent of all Australian wine, even if it has yet to make a serious impact in France and hardly any in the United States, where plastic corks are much more popular, even though the screwcap was originally invented in New York in the late 19th century. 

When faced with what to wine producers and wine drinkers seemed irrefutable evidence of an increase in TCA-tainted wines from the 1980s when, as Taber reveals, Portugal’s cork forests were showing the effects of the 1974 revolution, the cork industry argued that the fault lay not with the corks themselves but with wine producers who had mistreated their corks. It is certainly true that cork was not the culprit for all TCA infections. Bordeaux wine researcher Pascal Chatonnet, profiled on these pages some years ago, specialises in the analysis of TCA and similar winery infections which come not from corks but from the likes of the chlorine once routinely used to sterilise winery equipment and from a particular wood treatment. His company Excell has made a speciality of discreet analysis and disinfection in properties such as, most famously, Châteaux Ducru-Beaucaillou, Canon and Latour, each of whose wine cellars has been completely reconstructed since troubles in the 1980s. Taber suggests why such problems were initially overlooked by the wine producers themselves. “TCA causes anosmia, the temporary lack of smell. In those distant times before the Internet, winemakers were writing letters to each other asking if they had the same trouble. When the letters were opened, the recipients would often pull back in shock because of the offensive smell drifting out of the envelope.” 

Even as recently as 2000 the cork producers still did not understand the depth of the wine industry’s rage at the extent to which cork problems were blighting their wines’ reputation. Arguably even worse than out and out TCA contamination is low level TCA taint which simply robs a wine of its fruit and makes the consumer blame the wine not the cork – one of the few aspects of the story underplayed by Taber. In February of that year Antonio Amorim flew with the topflight scientist Miguel Cabral he had at last hired to try to sort out the TCA problem to Australia for a meeting with six of corks’ harshest critics from the wine industry there (the Australians had long suspected they had been fobbed off with the poorest quality corks because they were so far away from Portugal). Over dinner in an Adelaide hotel the Portuguese visitors had to withstand more than four and half hours of sustained attack, relieved only when Amorim took a sip of the local water and was able to point out that it was contaminated by TCA too. On the way out of the restaurant, we are told, Amorim whispered to his new employee, “I don’t ever want to go through a meeting like that again in my life. I don’t care what it costs: just fix this problem!” 

We have a lot to thank the Australians, and Éric Hervé who developed the TCA-testing procedure, for. Since then the old habit of drying cork bark on the damp ground encouraging all sorts of moulds has been abandoned by the bigger cork producers and Cabral has come up with a way of using steam to dramatically reduce TCA levels in Amorim’s corks. The cork industry is busy inventing new stoppers such as Diam, the successor of the ill-fated Altec that went from zero to sales of 2.5 billion stoppers in less than five years (it developed taint in the end too thanks to the glue used to bind its cork granules). Today, of the 20 billion wine bottle stoppers used each year (a number that is still rising thanks to the switch from bulk to bottled wine), 16 billion are natural cork in some form, 2.5 billion are the plastic corks which are being improved but still don’t offer a perfect seal over long periods, 20 million glass stoppers and just 1.5 billion, but growing fastest, the hotly defended screwcaps. 

Taber covers the screwcap related problems of reduction (bad egg smells) associated with screwcap liners and the possible downside of the copper fining needed to avoid them. He also mentions their less robust qualities during transport. He is utterly fair in his treatment of the bottle stopper options and, like me, feels a tendresse for natural cork but is delighted that it no longer enjoys an ill-deserved monopoly on keeping the air out and the wine in.