Granite: Rock of grandeur, rock of ages

Geologists refer to this featureless appearance as “massive”, and it gives the rock a certain majesty. Thus “Beethoven’s Fifth symphony has a granite-like, statuesque grandeur.” And it allows remarkably large blocks to be quarried; the ancient Egyptians utilized it for their great temples and obelisks, still some of the largest stone monuments ever fashioned. All this, together with its strength, has given granite a reputation of unshakability. (Chairman Mao’s tomb is of granite “as unshakable as Mao’s self-belief in his brutish doctrines”; Donald Trump is said to have “a granite confidence in human corruptibility.”) This perception of solidity has long made the rock a favorite material for prestigious major buildings—and to give banks an indestructible look.

An important reason why Port producers along the Douro in Portugal have traditionally avoided the granite there is its massive nature. Water is crucial in this arid area (there are cacti in some vineyards)—but unlike the nearby schists, which allow the winter rainfall to percolate down their vertical planes of weakness and be stored for the torrid summer, the granite gives no such opportunity. In fact, the vine roots can barely penetrate the featureless granite.

There’s a great deal of granite in Portugal. It’s seen in winery buildings in Estramadura (Lisboa) in the south, all the way up to the Vinho Verde region in the north—for example, in tanks for fermenting and maturing the wines. Granite tanks are now newly fashionable; away from Portugal they’ve recently been installed in, for instance, the Torres winery in Spain’s Pazo Torre Penelas (Rías Baixas), the Schmitges winery in Erden, Mosel, and the Giesen winery in New Zealand’s Marlborough. But nowhere is there a more famous example of granite being used inside wineries than the lagares of the Douro region. Surely a classic image of the traditional wine world is a throng of exuberant souls dancing on grapes, with purple juice dribbling down their bare legs and feet. The ritual still continues at some quintas, almost always carried out in stone troughs, usually of granite. 

Blocks of rock were quarried for this purpose in places such as Vila Pouca de Aguiar, Portugal’s self-styled granite capital, where the granite is sufficiently massive for slabs to be sawn from them and formed into rectangular tubs. (In Vale de Mendiz is a circular example, its builder apparently trying to prevent the stompers from hurting their toes in square corners.) Granite is now rarely produced for new lagares; those being used today are centuries old, once hauled to the Douro area on ox carts.

Worlds of granite

Huge volumes of granite, albeit formed at depth, are now at Earth’s surface. They dominate the mountains that parallel the Pacific Coast all the way from the Rockies of British Columbia down to Patagonia, yielding important vineyard soils. When you stand among the vines on the flat floor of the Elqui Valley in Chile, those soaring mountains all around you are carved in granite. At the experimental vineyard way up in the Peruvian Andes, near Machu Picchu, is the ancient Inca citadel with its stone buildings clustered beneath the towering peaks, and all the rock you see—including the buildings—is granite. The rock accounts for the mountains around Stellenbosch and Franschhoek in the Western Cape of South Africa and, from there, stretches northwestward for 125 miles (200km) through Darling and Swartland. Granite around Armidale in New South Wales continues all the way to the Granite Belt wineries of Queensland, a distance of more than 155 miles (250km).

For some wine enthusiasts, archetypal granite country may be Beaujolais, though actually rather less than one quarter of the region has granite bedrock. It’s in the ten Beaujolais crus that the rock does come to the fore—Chiroubles, for example, is entirely granite. And it’s tough stuff. In places where the overlying crumbly soil is particularly thin, growers have had to use drills and crowbars to loosen the substrate for the roots. Pink feldspar is easily visible in the rubbly vineyard stones. The upper reaches of the twisting D86 and D119 roads that climb above Chiroubles village give glorious views across the terraced vineyards, strikingly buttressed in places with piles of the local pink rock.

Moulin-à-Vent is largely underlain by granite, though by no means wholly. Some of the most highly regarded lieux-dits (such as Le Clos, Le Carquelin, Champ de Cour, and Les Thorins) are granitic and flank the old windmill that gives the commune its name. The mill, used centuries ago for producing flour, is now much restored and its walls stuccoed but, unsurprisingly, its walls are made of granite. Down in the Côte de Brouilly cru, the celebrated rock so conspicuous all around is often called granite—but wrongly. It’s a dark blue-gray color, unlike granite, and much used in the local buildings, where a close look shows little in the way of quartz and potassium feldspar. Technically, it’s a rock called diorite.

Around Clisson in France’s Muscadet country, the bedrock is granite, and its extent defines the Clisson cru communal. Granite rules here—not only for the 20 or so wine producers but for the town itself. Its bridges, churches, and houses are all built of the local rock, as are the walls of the wonderful 15th-century timber-framed market hall. And granite is still relevant today, with disused quarries in the area providing top-notch technical climbing walls. Can it be coincidence that a three-day music extravaganza takes place here each June, the heavy metal Hellfest, featuring top rock bands?

The immovable rock moves

In some vineyard areas with granite bedrock, the overlying soil is derived directly from underneath, apart perhaps from some slipping down hillslopes. This is the case, for instance, in parts of Alsace. The vineyards there stretch along the steep hillsides caught in the intricate fault zone that separates the easterly Rhine Valley from the Vosges to the west, upstanding partly because of their tough granitic foundation. A few vineyard sites have soils largely of granite scree tumbled down from the adjacent Vosges.

Examples are found at Brandt and Wihr-au-Val in the Vallée de Munster; one grand cru wine from Sommerberg in Niedermorschwihr is simply called Granite. There are several different granite bodies involved, so the soil colors vary with the mineral content of the parent rock; at Dambach, the material is a buff pink, as in the town walls, whereas the ruddy feldspars at Châtenois give a deeper brown-red. Many of these hillslope sites are crowned by old castle ruins, perhaps most famously at Schlossberg, Alsace’s largest grand cru, overlooked by the brooding granite walls of Kayserberg Castle.

On the other side of the world, the vineyard slopes of the granitic Strathbogie Ranges, northeast of Melbourne, are less steep than Alsace, but nevertheless much of the granite soil has slipped downhill. The vineyards have soil peppered with large granite boulders that have been transported downslope to their present position, but that the bedrock is granite is shown by the imposing crags all around. This was Ned Kelly country. The outlaw spent 16 months on the run here, presumably using the cover provided by the bluffs and boulders of these rugged granite hills.

There are vineyard areas with soils in which granite is important even though the bedrock may consist of something else. In most cases, the granite has been taken there as pebbles and boulders by rivers, and nowhere is this more apparent than in the great valleys of central Chile. Charles Darwin realized this, because back in 1834 he was recording “numerous large blocks of granite” along the Maipo and Cachapoal rivers, even though “granite does not occur within a distance of twenty leagues.”

The granite of these alluvial pebbles continues to weather in place; they can be sufficiently crumbly for vine roots to be able to grow through them, to reach the more clayey material below. Some pebbles even fall apart when picked up. One producer believes that the degree of the weathering affects the wine; more intact granite pebbles give “medium-volume wines, with good weight on the palate, and well balanced,” but increasing degradation leads to wines with “greater structure, a broader and heavier feel in the mouth, and smooth tannins.”

Over on the Argentinian side of the Andes, there is much more input into the alluvial gravels from nearby volcanoes, such as Tupungatito. Consequently, many of the pebbles are made of rocks like the eponymous andesite and basalt. In places, however, granite is significant. In Gualtallary, for example, in the north of the Uco Valley, the alluvial soils of the Las Tunas River contain granite boulders reaching the size of cannonballs.

Of granite and grapes

I often read that particular kinds of grapevine “prefer” specific geological soils and, conversely, that certain kinds of geology are best for particular cultivars. I’ve seen the notion presented in tables, with stars for the favored combinations, like Riesling and slate, Cabernet and gravel, Chardonnay and limestone, and so on. And granite? Well, Gamay and Syrah. Thus—so the idea goes—for quality wines from these two cultivars, you need granite soils. 

But surely these associations are simply reflections of certain classic European sites? It seems to me that which particular cultivar grows well at a site depends on the mix of all the relevant factors, and not just on the geology (not to mention the kind of rootstock onto which the cultivar has been grafted). Clearly Gamay thrives in the granite soils of Beaujolais, and similarly Syrah in the northern Rhône, but both cultivars also flourish and yield superlative wines in the other soils of those two areas. In the Rhône, for example, the Côte-Rôtie is not granite, and the Hill of Hermitage has soils other than granite. And conversely, Condrieu is composed of granite but isn’t planted to Syrah.

It’s similarly diverse elsewhere in the world. Syrah vines obviously thrive in the granite soils of, say, South Africa’s Swartland and Paarl, but they also flourish in Australia’s Barossa, New Zealand’s Hawke’s Bay, and Washington State’s Yakima Valley—none of which involves granite. The Paarl vineyards also grow successful Pinotage, Petite Sirah, Viognier, and Grenache. Wineries in the Sierra Foothills of California are proud of their granitic soils, but here it’s Zinfandel that rules, together with other cultivars that yield outstanding wines of their type: Barbera, Petite Sirah, Mourvèdre, and many others. 

Opposite: The granite range that towers above vineyards in Stellenbosch, South Africa, stretches north for 125 miles through Darling into Swartland. Photography © fokke baarssen / Shutterstock.