Vines love a challenge and great vines thrive where little else grows: in volcanic ash and rock, for instance, and even in sand. The more a vine has to struggle in search of water, and the deeper the roots go, the more it will flourish. This is one, but only one, aspect of that almost mystical concept, terroir, so beloved of French wine producers.

A great terroir consists of many different elements, all in perfect balance and harmony. But the best terroirs require minimal intervention because the vines are “happy”, coping unaided with prevalent conditions, whether frost, hail or humidity. One of the greatest of all wines, Domaine de la Romanée-Conti, epitomises the mystery of terroir. It sits on limestone that’s 175 million years’ old, allowing roots to tunnel to great depths from which vital nutrients are drawn. Terroir can be even more localised: contiguous plots within the same vineyard produce very different wine; hence the scarcity of Romanée-Conti, produced from one small plot, which gives the whole domaine its fabled name.
But of all the elements that make a great terroir, soil is central, and topsoil is one of the chief factors that contributes to a wine’s essential character.