Why Volcanic Soil Makes Remarkable Wine

Nobody would choose to farm on a volcano. The ground is steep, the soil is thin where it is not absent, water drains away instantly, and there is the obvious problem of the volcano.

And yet some of the most interesting wine in Europe comes from exactly these places, made from vines that are among the oldest still producing anywhere, in vineyards that look nothing like vineyards. There are three reasons, and only one of them is about soil chemistry.

Volcanic soils are rich in potassium, magnesium, phosphorus and trace minerals, released as the rock weathers, and they tend to be free-draining while still holding moisture at depth. For a vine, that combination is close to ideal: enough nutrition, no waterlogging, and a reason to send roots down a long way in search of water.

Whether you can taste the rock is a genuinely contested question. Winemakers on Etna, Santorini and the Canaries will tell you about salinity, smoke and a flinty edge, and the wines really do share a family resemblance across regions thousands of kilometres apart. Whether that comes from minerals in the soil, or from the altitude, the temperature swing and the grape varieties that survived in these places, is argued about at length and not settled.

The honest position: the wines are distinctive, the soil is unusual, and the causal chain between the two is less direct than the marketing suggests.

This is the part of the story that is properly extraordinary.

In the second half of the nineteenth century, phylloxera, a root-feeding aphid accidentally imported from North America, destroyed the great majority of European vineyards. The eventual solution was to graft European vines onto resistant American rootstock, which is why almost every vine in Europe today is grafted, and why the pre-phylloxera era is spoken of the way people speak of a lost civilisation.

The louse cannot move through loose sand. It needs to travel through soil to reach roots, and in fine volcanic sand and ash it fails.

So a handful of places escaped: Santorini, whose vineyards sit on volcanic pumice; Lanzarote, planted in ash; parts of the Canaries; pockets of Etna and the Azores. The vines in those places were never destroyed and never grafted. Some Santorini rootstocks are estimated at several centuries old, kept going by cutting the vine back and letting a new shoot grow from the ancient root.

The wine you are drinking on Santorini may come from a plant that was alive before phylloxera existed as a European problem.

Each of these places invented its own answer to the same set of problems: wind, sun, and no water.

Santorini weaves the vine into a basket, called a kouloura, lying on the ground with the grapes growing on the inside. It shelters the fruit from the meltemi wind, which would otherwise sandblast it, and shades it from the sun. From a distance the vineyards look like fields of woven baskets, and from a car they look like nothing at all.

The Azores built currais: a grid of dry-stone walls made from lava blocks, each enclosing a small plot, protecting the vines from the Atlantic wind and salt. The landscape on Pico is a UNESCO World Heritage Site for precisely this reason, and it is best understood from above, where the pattern is unmistakable.

Etna went up instead of hiding. Vineyards run from around 400 metres to over 1,000, which at that latitude means warm days and genuinely cold nights, and slopes divided into contrade whose soils differ from one lava flow to the next. That combination has led to the comparison with Burgundy, which is doing some work but is not absurd: the wines from adjacent plots are noticeably different, and the reason is which century's eruption is underneath them.

Vesuvius makes Lacryma Christi on the slopes above Pompeii, from vines growing in the deposits of eruptions that killed the people who farmed here before.

Wine is the most reliable volcanic experience there is. It does not depend on the weather, the alert level, or whether anything is erupting, and it happens at a comfortable altitude with somewhere to sit down.

It also solves a practical problem: on Etna and Vesuvius the summit is best in the morning, which leaves an afternoon. A vineyard on the lower slopes is fifteen minutes away and looks up at the mountain you were standing on. Combination tours exist for exactly that reason and they are one of the few combination products we would actively recommend.

Two things worth knowing. Harvest is late here, sometimes into October at altitude on Etna, so the vineyards are working later in the year than you might expect. And the small producers are genuinely small: several of these regions are made up of growers with a few hectares, which is why booking ahead matters more than it would in Tuscany.