Bretty, Bretty, Brett 12 March 2006

Winemaker Tom Lubbe questions whether Brettanomyces is always a fault

• This contribution follows lengthy debates held on the Grape website. Click here for recent discussion.

It is fantastic to see such lively debate about Brettanomyces in wine but I am a little troubled by some of the perceptions evidently current in professional wine circles in South Africa (and often beyond) as regards causes and effects. Some interesting research has been initiated over the last fifteen years, notably by Chatonnet (France), Burns (Australia) among others and evidently this has largely been ignored by contributors to the Grape debate on Brett.

A 2003 Masters of wine thesis, entitled ‘the role of brettanomyces in the Production High Quality Syrah-based Wines’ by Sam Harrop, provides a useful synthesis of available literature and outlines an interesting experiment by the author wherein 25 world-class syrah-based wines were tasted and evaluated by a panel of wine professionals, and then tested for volatile phenols 4-EP and 4-EG. (Worth noting, as Harrop does, ‘the ratio between the two phenols is also key to overall flavour expression’.)

Twenty-four of the twenty-five wines contained the volatile phenols 4-EP and 4-EG associated with Brett activity. The top four ranked wines had levels over the commonly held ‘sensory threshold’. Often referred to is the Australian Wine Research Institute’s 425mg/l of 4-EP and Burn’s figure of 50-100mg/l for 4-EG). The one wine in Harrop’s tasting with 0 mg/l 4-EP and 0 mg/l 4-EG was ranked 23^rd in preference and ten tasters identified it as being affected by the volatile phenols! Go figure.

Desirable characters

While there are perhaps some masterly denizens in SA wine circles who can sniff brett at fifty paces, the more humble Chatonnet, among others, has noted the difficulty of realistic sensorial evaluation of Brett activity, as the compounds in the volatile phenols are often indistinguishable from certain forms of reduction, and indeed certain varietal characters. Chatonnet notes, as does Harrop, that these compounds can be highly desirable, at controlled levels, in the production of quality wine. (Varietal characters are also quite prized in SA wine-making as we know.)

The demand for wines devoid of either ‘fault’ (Brett and reduction) is thus appropriate in the production of mass-produced, low-quality wines which lack the primary fruit quality to ensure these develop as complexity-giving tropes rather than pleasure-destroying stink-makers. Australia, further along in the throes of a brett frenzy (the Australian Wine Research Institute mean analysis in 2003 was 805mg/l of 4-EP and 108mg/l of 4-EG), still managed to gain a majority market-share in the UK despite producing so much ‘faulty’ wine.

Cellar or grape?

The over-riding assumption that levels of volatile phenols are simply related to cellar hygiene is as useful as it is intelligent. This is certainly one factor and assuredly dirty pipes and floors aren’t going to help, but a more informed over-all picture is necessary. (Or there is always running around in circles, screaming ‘burn the witch!’, as a sweet method to restore consumer confidence.)

While it has not been conclusively shown that Brett is imported to the cellar from the vineyard, there is no question that fruit quality plays the starting role (as it always should) . On the most fundamental level, high quality fruit does not have a high pH, and low pH (essentially a high level of acidity) has a major role in inhibiting the growth of Brett colonies, also greatly influencing the efficacity of free sulphur’s value as active sulphur .

Problematically, in relation to Brett growth, current wine-styles favour late-harvested grapes with high fermentable sugars (leaving higher residual sugars as yeasts struggle to finish), higher natural pHs, and higher levels of dry extract; all of which are factors contributing to the development of thriving Brett colonies. The greedy little beggars will even make a meal of the thiamine used by the hapless modern winemaker to try to finish that lagging ferment in his/her bid for Parker glory. (And yes, the sugars found in highly-toasted new barrels are also grist to their mill) An optimistic no-filtration on top of this gooey recipe and the groundwork is well-layed for an explosion in bottle of active Brett populations, resulting in ever increasing levels of volatile phenols, so testing the young wines isn’t necessarily going to make the long-suffering sommelier’s life any easier, or result in a happier consumer who has paid out for the pricey stink-bomb. Bad luck for them.

Good wine

Alternative to brandishing useful technical sheets in the face of disgruntled Saturday night sippers, the modern sommelier is being forced to ask the mighty question ‘What is good wine?’ And having made that decision based on taste (their profession after all), being prepared to defend it. The same goes for the journalist or passionate consumer, who do not want to rely on the spoon-fed sure-thing . ‘Solving’ the technical problem of the day is not going to make better fine wine, and thus happier drinkers. (Whatever happened to pleasure in wine?) For sommelier, journalist and wine-lovers to put pressure on the issue of primary production is far more useful than ambulance-spotting at the bottom of the cliff. Those gardeners among wine-lovers who recognise good soil should look in a vineyard – try and find an earthworm if you dare.

Viticulturally South Africa is well-placed to produce, (depending on equipment and skills of wine-maker) more or less tasty commercial wine at competitive prices. As long as local winemakers confuse dry-extract with fruit quality and refuse to insist on decent compost on their vineyards, there will be very little truth coming from their soil. It is great that there is a campaign for biodiversity around the vineyard but in relation to wine quality (not quantity perhaps) some biodiversity within the vineyard can also be a good thing. If the wine-maker is then willing, the result is flavour at lower alcohols, healthier fermenting wine with lower natural pH and less residual sugar. Further if the pipes are clean back at Central, not to mention the barrels, and why not a judicious sulphur regime in elevage, we are well on the way to containing bad brett and making more pleasurable wine – for drinking, if not for winning prizes.

PS As a producer I have a vested interest in trying to appear more knowledgeable than I am in a bid to flog more of my product.

• Tom Lubbe is an owner of Matassa in Roussillon, and of The Observatory in the Swartland