Carrots, celery – and Shiraz

Jefford on Monday

Will there, one day, be a Department of Terroir Studies at a leading academic institution? Who will be its first professor? How many disciplines will jockey for a position in its hive?

We’re still some decades away from this glorious moment, I suspect, but each new year takes us a little closer. It will, note, be a science department; those (like me) tutored in the humanities are doomed to linger at the consuming end of the terroir spectrum, though it behoves us all to try to master as much of the necessary science as we can.

There will be many agricultural applications beyond wine: the practical purpose of studying terroir would be to maximise the quality potential of any high-value crop destined for sensual scrutiny rather than to fill a commodity or subsistence role. ‘Luxury’ agricultural products will play an important role in an increasingly prosperous world. Once we can all eat, we should eat better: enter terroir.

At this time of year here in France, for example, I love to buy carottes des sables, seaweed-fertilised and grown in the sandy soils of Créances in Normandy, then hand-harvested and sold unwashed, still covered in sand. They smell of sawdust, as every great carrot should; fine rootlets sprout from their sides; they are dense and tight textured, with a fresh, sappy sweetness – much better, in truth, than any ‘organic carrot’ I have ever eaten (even if I then spend a lot of time sweeping sand off the kitchen floor). Why so good? The Department of Terroir Studies at my University of the Future will be able to tell us, just as it would explain why the stupendously strong, firm celery grown in the Adelaide Hills is unmatched, eclipsing any celery I have ever bought in Europe.

One of the most impressive synthetic attempts at explaining wine terroir yet to come my way was published last April, for the growers of the Barossa and in particular the ongoing ‘Barossa Grounds’ project. This was a paper authored by Scott Robinson and Neil Sandercock of the South Australian government agency PIRSA, entitled ‘An analysis of climate, soil and topographical information to aid the understanding of Barossa terroir’. It can be freely downloaded here.

One of the things that this study revealed was that any future Department of Terroir Studies would certainly need computer experts and considerable computing power, too. Robinson and Sandercock brought together data relating to soil, elevation, rainfall, temperature and growing degree days, then combined all the data inputs, giving a set of 600 unique terroir combinations.

Mapping these in a conventional way using colour variants produced a result of such chaos that the authors decided to make a second, simplified version (the justification for this being that there was a strong mathematical correlation between temperature, rainfall and elevation data). The new map gave a more coherent account of what might tentatively be described as the valley’s terroir units.

Even the first map, though, had been a gross simplification. The authors point out that there are at least 40 soil ‘themes’ they could have looked at, and they chose just one: water-holding capacity. There were other data sets which weren’t in the study at all (such as wind, slope and aspect – and no terroir study of Southern France or South Africa would make any sense at all without reference to wind). This study is, thus, no more than a first sketch of an almost unimaginably complex picture.

For all that, it is compellingly interesting, and a more coherent and systematic account of terroir than any I have ever seen emanate from Burgundy, from Bordeaux or from any other European fine-wine region. It’s not that the data is missing elsewhere; it’s just never synthesized in this way. One of the very first tasks for the Department of Terroir Studies would be to define a universal, methodological framework for the basic assessment of terroir – as Robinson and Sandercock have tried to do. Then we can start to make all the comparisons between regions which we either guess at or define with almost meaningless sampling partiality at present.

In practical terms, the main message of this paper is that the Barossa Zone (which includes the Eden Valley and its High Eden sub-region, remember, as well as the Barossa Valley proper) is much more diverse than most of us realize. Almost 50 per cent of the planted area is under 280m, for example, but 5 per cent is at over 450m. Pewsey Vale gets twice the annual rainfall of Nuriootpa or Light Pass, and the growing-season rainfall contrast is nearly as stark – but those central valley locations can have up to five times the water-holding capacity of the high, bony hills. Mean January temperatures vary enormously (from 19.5˚C to 23.1˚C). The raw growing degree-day data is even more interesting, since not only does it again illustrate a huge internal contrast (1373 GDD on the edge of High Eden compared to 2076 GDD as you approach Gawler), but it also shows that parts of ‘the valley floor’ (like Bethany and Krondorf) are much cooler than others (like Lyndoch or Rowland Flat). We usually speak of Barossa in terms of its averages – but this paper shows just how misleading that can be.

These nuances are well understood by those who live and work in the Barossa. One of the most fascinating single days of the fifteen months I spent in Australia between 2009 and 2010 was a day of vineyard visits with Penfolds Peter Gago and consultant Paul Giorgiadis, who have spent years tasting fruit throughout the valley, grading it and seeing how it emerged as components for the company multitude of blends. Fruit from every sub-region had a character of script-writer’s clarity for them, as it does for the farmers who own the vines and have tended them for many generations.

Allowing those characters to emerge in a set of sub-regional wines, though, is a much bigger challenge, since extractive winemaking without adjustment is still seen by most Barossa winemakers as not even possible, let alone desirable. That, though, may change in time. Robinson and Sandercock’s work provides a fine incentive, for those who were so minded, to allow the differences perceptible in the grapes full, limpid and sincere expression – as well as offering a starting point for understanding exactly why Barossa’s Shiraz is so different to Syrah in Cornas, in Gigondas, in Walla Walla or in Hawke’s Bay.

Columnist Introduction

Andrew Jefford is a columnist for both Decanter magazine and www.decanter.com, Jefford has been writing and broadcasting about wine (as well as food, whisky, travel and perfume) since the 1980s, winning many awards – the latest for his work as a columnist. After 15 months as a senior research fellow at Adelaide University between 2009 and 2010, Andrew is currently writing a book on Australia's wine landscape and terroirs. He lives in the Languedoc, on the frontier between the Grès de Montpellier and Pic St Loup zones.

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