Finding fault

Friday, June 1st, 2012

The International Wine Challenge was held at a cold and rain-lashed Lord’s cricket ground in London a few weeks ago. Numbers of entries were once again up, way past 12 000 samples from all over the world, organiser Charles Metcalfe reported on day one of the judging.

One of the most interesting features of the Challenge is the faults clinic delivered by Sam Harrop who did his Master of Wine dissertation on this subject. A voluntary presentation held at the end of the first day’s judging, Harrop revealed that this year an additional rigour was being applied to fault finding at the IWC. Two Australian Wine Research Institute experts – Geoff Cowey and Martin Day – were drafted in to assist him. Not only that, but two full pallets of faulty wines were shipped back to Australia for scientific analysis using GCMS (gas chromatography – mass spectrometry).

Previously, panels have identified faults and called for a second bottle. The faulty bottle has then been assessed sensorially by Harrop. He admits that he is conservative in his assessment – as are the judging panels – and up to 60% of wines deemed faulty have, in fact, not been. When standing in judgement on a producer’s wine there is always a decision to err on the side of conservatism, giving the wine the benefit of the doubt and a second chance rather than simply rejecting it out of hand.

Nonetheless, since the fault finding element of the IWC was begun in 2006, more than 90 000 bottles of wine have been assessed. Of those, 6.4% were deemed faulty. Harrop presented not only a clinic on what broad faults to look for and identify (sulphides, TCA or musty cork taints, oxidation and brettanomyces and volatile phenols) but some interesting statistics on his years of research.

“We’ve seen the knowledge of faults and wine flaws increase dramatically,” said Harrop. Gone are the days when a wine was simply written off as ‘corked’. Nowadays people actually specify faults more keenly – oxidation, reduction, TCA, brett, mercaptans or sulphide problems. As a consequence the industry “standard” of 5% for cork taint has dropped to 2.7% at the IWC.

Winemaking faults are the issue nowadays, Harrop maintains. “With a focussed approach, winemakers can reduce faults to almost zero! And there are huge benefits for the consumer,” he said.

He noted that as a percentage of entries to the IWC France, Spain and Italy had the worst fault record. “The New World is performing better than the Old World – but it’s not as simple as saying this is an Old World issue.”

Why are winemaking faults becoming more of an issue? Because of market trends – consumers want cleaner, fresher, less funky wines. Global warming is creating more ripeness in countries less used to it – and higher alcohols and thus higher sulphur compounds are the result. Finally, there is a movement towards more natural winemaking with less intervention and lower sulphur levels. Not only that, but people are more aware of faults than they were a decade ago.

Of particular interest to me was the ‘lesser fault’ category – rot, vine stress, SO2, pinking and volatility. Vine stress in particular is the label that is being applied to what has previously been known as the ‘South African green character’. “Vine stress is not an ideal descriptor but we haven’t been able to identify one specific thing or a chemical compound,” they said.

The good news is that Cowey, Day and Harrop said it was not unique to South Africa.  “It’s being seen in hotter countries such as Australia and India too.” Common to all are extreme heat, lack of irrigation and a lack of true phenolic ripeness on the resultant wines.”

One worrying increase the trio noted was the rise in screwcap reduction. Australia, New Zealand and Chile account for 60% of all screwcap reductive faults picked up at the competition but that could potentially be attributable to a preference over cork closures. “The potential for this to become a major world problem is huge as Europe switches to higher incidence of screwcap closures.”

“Most consumers won’t notice something like screwcap reduction but the problem is that the fault is suppressing a lot of the fruit expression which consumers love on their wines.”

This is just one area in which winemakers can adjust their pre-bottling sulphur regimes in order to prevent it from occurring.