Burnt Rubber: the great South African wine debate

Here's a film from an event held yesterday titled 'The Great Cape Wine Debate'. It involved a group of UK journalists and a select band of South African winemakers to discuss several current topics, focusing in particular on the 'Burnt Rubber' issue. The debate was organized by South African specialist Richard Kelley MW (of importer Richards Walford), and he gathered a stellar line-up of winemakers:

• Marc Kent (Boekenhoutskloof)
• Roelf & Michelle du Preez (Bon Cap)
• Gottfried Mocke (Cape Chamonix)
• Bruce Jack (Constellation)
• Chris Williams (Meerlust/The Foundry)
• Niels Verburg (Luddite)
• Carl van der Merwe (Quoin Rock)
• Eben Sadie (Sadie Family Wines)
• Callie Louw (TMV)
• Mike Ratcliffe (Warwick and Vilafonte)

So what is the 'Burnt Rubber' issue? In brief, it's the off flavour/aroma that many people have been noticing in South African red wines. Critics, largely in the UK, have been pointing out that too many South African reds show a rather off-putting burnt rubber character that immediately marks them as South African. In response, Jo Mason of Wines of South Africa got together a group of these critical journalists and presented them with a number of South African reds (as well as a few ringers) blind. They reached more-or-less a consensus on which reds showed the burnt rubber character, and these were sent to wine science researchers in South Africa for analysis to see if any offending characters could be identified.

The 20-minute video covers the discussion between the journalists and winemakers. It's evidently a sensitive topic- and a controversial one. It should be pointed out that this group represents some of South Africa's top winemaking talent, and their wines (which we tasted) don't show any hints of burnt rubber. As such, it's a little unfair to be putting them under the spotlight like this.

You can read more about this issue in the following pieces:

• Jane MacQuitty's controversial Times article from last year
• Decanter news piece
• An SA viewpoint from Grape

Danish reduction

Just back from Denmark, where I was attending Lallemand's technical conference. Last night, I arrived at Billund airport at 11.30 pm, and was driven 40 km to Horsens, for the Bygholm Park hotel (http://www.scandic-hotels.dk/) where we were meeting.

It's a beautiful setting, surrounded by attractive parkland (above). I was up early to put the finishing touches on my presentation, grab some breakfast, and then wander down to the conference room.

It felt like a rare luxury to be able to attend a scientific meeting. This was the first I had been to since I finished my day-job employment as a science editor. The open spirit of enquiry and generosity of spirit that you get at scientific meetings is to be marvelled at. [Science is one of the few truly cooperative human ventures I can think of that actually works.]

The program was as follows:

Technical meeting Sulphur compounds –production and sensory impact

Wine faults and their prevalence: data from the world's largest blind tasting
Jamie Goode and Sam Harrop

The genetics of sulfide taint production in Saccharomyces
Angela Lee Linderholm, Linda F. Bisson, Kevin L. Dietzel, Yeun Hong, Gagandeep R. Kumar, and Carrie L. Findleton

Formation of aroma-active S-compounds by Oenococcus oeni during malolactic fermentation in wine-like media and wine

Doris Rauhut, Volker Schäfer, Beata Beisert, Bernd-Christoph Lochbühler, Magdalena Gawron-Scibek and Sibylle Krieger-Weber

Optimizing wine quality through the application of flavour-active yeast strains and nutrients.
Chris Curtin

A reduction in smell?
Michael Moisseeff

I'm happy to expand on any of these if there's any interest. I thought all the papers were excellent. The most entertaining by far, though, was the final one, which featured some fun with scents. Moisseeff works the audience brilliantly - he's like a stand-up comedian. I should really blog on his talk separately.

I left after a quick beer to catch my return flight, and was back home by 10 pm. Utterly painless journey, in part because I was flying from a tiny airport in an organized sort of country. A really good day.

Wine faults in Denmark

I'm currently enduring that special part of hell also known as Gatwick South Terminal, en route to Billund in Denmark, where tomorrow I'll be presenting a paper on wine faults at the XXth Entretiens Scientifiques Lallemand. I've never been to Denmark before, and seeing as I'm coming back tomorrow evening, I doubt I'll see much of it. Apparently, Legoland is in Billund.

Most of my talk will be based on the last three years' data from the International Wine Challenge. These data have been collected by Sam Harrop MW (pictured), who is a co-author on this paper, and they're really exciting. The strength of this data set is that it's large (c. 15 000 wines opened, 10 000 separate wines entered); it's a 'real world' analysis of faults; some reasonably smart palates have been involved in getting the data; and there are multiple years' worth of data to look at. The weakness is that it's sensory analysis and not chemical, and also that faults such as reduction and brettanomyces may well be under-reported, as well as the possibility of false positives.

One of the exciting things about the paper is that it will contain a regional breakdown. Some countries are over-delivering oxidized wines, bretty wines, and wines with reduction defects.

There's a limit to what I can say about the data here, because they aren't mine to share. But I can say (and these are provisional figures from an ongoing analysis, so please don't quote them elsewhere) that cork taint is hovering around 3% all three years. Screwcap reduction is around 2.5%, but going down. With 2008, it seems that winemaking faults are overtaking closure faults as the chief cause of problems. Around 7% of wines entered into the challenge show some sort of fault, which isn't really good enough.