Why the Hill Faces East

Stand at the top of the vineyards above Aloxe-Corton on a clear morning and the geography explains itself in about four seconds. Behind you the land rises into scrubby limestone plateau, thin-soiled and wooded, good for goats. In front of you it falls away in one continuous slope, and then, quite abruptly, it stops falling and becomes a plain that runs flat to the horizon. The vines occupy the falling part. Almost nothing above them is planted, and what is planted below them sells for a fraction of the price.

That break is a fault. Around thirty million years ago, as the Alps were rising, the block of ground to the east (what is now the Bresse plain and the Saône valley) subsided along a line running roughly north-north-east. The block to the west did not. What was left is a scarp: a broken edge, about fifty kilometres long, exposing in cross-section a stack of Jurassic limestones and marls that had been laid down horizontally on a warm shallow sea floor a hundred and fifty million years earlier.

Nothing about this was arranged for the benefit of pinot noir. But three consequences follow from it, and between them they account for most of what Burgundy is.

The first is aspect. A scarp that faces roughly east catches the morning sun at a low angle onto tilted ground. Tilting matters more than it sounds. The same quantity of light falling on a sloping surface is concentrated into a smaller footprint, so the ground warms faster and further than flat land beside it. At this latitude, at the cold northern edge of where pinot noir ripens at all, that fraction of a degree in mean temperature has historically been the difference between a great vintage and a thin one.

The second is drainage. Water runs downhill; so does soil. Over a few million years the top of the slope has been stripped to something close to bare rock, and the bottom has accumulated everything that came off it. This produces a gradient of soil depth from almost nothing at the crest to a metre or more at the foot, and a matching gradient of vine behaviour. On the crest a vine starves. At the foot it luxuriates, grows a great deal of leaf, and ripens fruit that tastes diluted. In between is a band, perhaps two hundred metres wide, where there is enough soil to survive a dry August and enough gradient to shed a wet one. Take a map of the grands crus and lay it over a contour map and you will find that the two are very nearly the same drawing.

The third is exposure in cross-section. Because the fault cut through a layer cake, different bands of rock outcrop at different heights along the slope, and they outcrop repeatedly for fifty kilometres. This is why a difference detected in one village recurs in the next one along. Burgundy is not a mosaic of unrelated parcels; it is one geological sequence, seen again and again.

The obvious objection is that plenty of places have east-facing limestone slopes and do not produce Chambertin. That is entirely correct, and it is worth holding on to, because the geology is a necessary condition rather than an explanation. What the hill supplied was the possibility of detectable difference between one hectare and the next. What turned that possibility into a thousand named parcels was a thousand years of people bothering to notice. The rock did the first half of the work. The chapter after this one is about who did the second.