Burgundy is a fault line divided into 1,247 names

Drive south from Dijon and the road runs along the foot of a low cliff. On the left the ground rises for a few hundred metres and then flattens into a limestone plateau with woodland on it. On the right the ground drops to the plain of the Saône. Between those two flats, on a slope one or two kilometres wide and sixty kilometres long, is almost all of the most expensive wine land in the world.

The whole Côte d'Or is one geological structure: a fault. The block to the west stayed up, the block to the east dropped, and the hinge between them is the slope the vines are planted on. Everything else in Burgundy — the hierarchy, the prices, the argument about which plot is better — is an argument conducted on that single hinge.

What an east-facing slope does

Four things, and none of them is mystical. First, aspect: the slope faces east or south-east, so it gets morning sun and dries early, which matters in a marginal climate where rot is the main risk. Second, drainage: the slope sheds water, so the vines are never comfortable. Third, frost: cold air drains down and pools on the plain, so the villages at the bottom of the slope get the frost and the mid-slope does not. Fourth, depth: the soil on the slope is thin — often less than a metre over the limestone — so the vine's roots go into cracks rather than into a reservoir.

The soil is not one material. It is a band of Middle Jurassic limestones and marls, tilted and partially eroded, so that two plots a hundred metres apart can sit on different mixtures of clay and limestone. Clay holds water; limestone drains it. The proportion between them, plot by plot, is the physical fact the whole hierarchy claims to describe.

The names are the fence at field scale

In 2015 UNESCO inscribed the Burgundy climats — 1,247 named parcels — as world heritage. A climat is not a soil type. It is a delimited parcel with a name that has been used for centuries, whose boundaries were fixed by the same process as the appellations in the first article: notoriety first, geology as the explanation.

So Burgundy is the same legal machine as the rest of France, zoomed in. An AOC like Chablis draws a fence around a district. A climat draws a fence around four hectares. The result is that the most valuable agricultural land in France is measured in ouvrées — a quarter of a hectare — and that a producer's entire business can be a single row of vines on the correct side of a stone wall.

Why the fragments

The Clos de Vougeot is fifty hectares behind one twelfth-century wall. It has about eighty owners. That is not a market outcome; it is the direct result of a legal rule. The Civil Code of 1804 made inheritance equal among children, and it did so as a matter of principle — the revolution's answer to primogeniture was to break up estates rather than preserve them. Two centuries later, a vineyard that was one holding in 1789 is a mosaic of rows.

The economics followed. Because no single owner has enough grapes to make a commercial quantity of a grand cru, the négociant system grew up to buy, blend and bottle. It is why Burgundy labels carry two names — the producer and the appellation — where Bordeaux labels carry one château. It also explains a fact that surprises every newcomer: in Burgundy, the producer matters more than the rank, because the same climat is made by eighty different people with eighty different standards.

The hierarchy is a sliver

Burgundy's classification runs from regional (about half of production) to village, to premier cru, to grand cru. The grand cru is roughly 1.5 per cent of the wine. That sliver is what the whole edifice is pointed at, and its existence sets the price of everything below it: a village wine from a good producer costs a multiple of a regional wine, and a grand cru costs a multiple of that, not because the winemaking is ten times better but because the supply cannot be increased. You cannot make more Clos de Vougeot. You can only pay more for it.

This is the honest reading of the slope: geology supplies a gradient, history supplies the names, and the law supplies the scarcity. A hillside that could have been one vineyard is, by design, twelve hundred.

How to taste the slope

Take two wines from the same village, one village-level and one premier cru, from the same producer if you can. The difference is not power. It is precision: the premier cru should have a clearer middle and a longer finish, the sensation of a narrower beam of flavour. Then take two premiers crus from adjacent climats and look for the same thing at a finer grain.

If you cannot taste the difference, that is information too. In Burgundy more than anywhere, the producer is the variable that dominates the geology — which is exactly what you would expect from a system where the land is divided among eighty owners and the fence is a stone wall a metre high.

This is entry 03 of Land & Terroir in About France. The pillar's argument — that France wrote soil and weather into law — is set out on the pillar page.