This is Abílio. He is a master stonemason. He has worked for us on and off for many years, and we are lucky to have him because he is one of the most skilled artisans plying this endangered trade in the Douro. But the fact that his skill is the culmination of an uninterrupted chain of expertise dating back to Roman times does not in any way make him obsolete. On the contrary, the recent recognition of the Douro as an UNESCO World Heritage Site has given his work renewed relevance today, and means that his labour is in considerable demand since existing walls are now protected and must be maintained.
These impressive schist walls are without a doubt the defining characteristic of the Douro landscape; the terrain is contoured by countless hundreds of kilometres of ancient walled terraces, many of them dating back to the days before the phylloxera epidemic devastated the region’s viticulture in the late 19th Century. Much of the almost unimaginable workforce that built the walls was made up of desperately impoverished Galician migrants who favoured this work as food and accommodation were also provided with the job. Many never returned home and their descendants still live here.
To give an idea of how long it takes to build one of these walls, Abílio and his assistant might be able to produce about two metres of a low wall in a nine-hour day. But as he points out, low walls are easy since the top metre of any wall is usually only around 50 cm thick. Higher walls require thicker bottoms to hold back the weight of the soil so they become exponentially more voluminous and time-consuming. Of course the outer face is always flat but the inner face must therefore be stepped back as its depth increases. It is obviously an extremely laborious process but that is the price that must be paid for Abílio’s brand of perfection. Well-constructed dry stone walls will last for much more than a century. Indeed, many of the pre-phylloxera terraces are still standing today, often now hidden under olive groves that were planted after the vines had given in to this terrible disease. These semi-abandoned terraces are poignantly known as mortuários, or graveyards.
Traditionally the Douro stone walls evolved for two reasons. Firstly, they were a by-product of the surriba, an operation that is essential before planting can be carried out in soils as rocky as ours. This process involves digging out the worst of the stones and breaking up the earth that is left behind. In the past, the stones that were dug out were placed on top of any rocky outcrops that were too big to remove, and thus formed the base of a new terrace. The second reason is of course that these walls effectively reduce the gradient of the steep hillsides, and therefore allow vines to be planted more densely and tended more easily.
Abílio’s equipment has not changed for millennia; his tool box contains just a hammer, a chisel, a plumb line and a measuring tape. The latter is the only concession to, well, not really modernity, but it does at least have a spring-loaded retraction mechanism. He uses the chisel to cleave the relatively soft schist with such precision that when he stacks one stone on top of another there is no room for a sheet of paper between them. And that is it: no cement, nothing but stones he picks up off the ground around him. Every so often he may leave deliberate drainage channels in the wall to prevent the build-up of outward pressure caused by water accumulating behind it.
Note that these holes should not be confused with pilheiros, which are similar-looking spaces through which vines could be planted horizontally and trained onto a sideways trellis that overhangs the terrace below. Should the drainage holes become blocked by mud and debris, the weight of the water retained on the terrace can cause a section of the wall to ruin. Additionally, wet weather also speeds up the rate at which this soft stone erodes and crumbles away. As a result, this winter’s torrential and incessant rainfall has been particularly destructive across the Douro, with hundreds of localised wall collapses. It is something of a blessing for Abílio, however, as he has never been busier.