Digging for flavor in Champagne. A scientist, a soil taster and two very different plots.

Why Champagne makes the perfect laboratory

Jamie starts on a hillside in Champagne, close to the northern limit for ripening grapes, where Chardonnay, Pinot Noir and Pinot Meunier grow on rolling slopes. Tens of millions of years ago this land lay under a warm sea, and the shells of countless tiny creatures settled into the thick beds of limestone and chalk that define the region today.

What makes Champagne useful for a scientist is not just the chalk but the variety beneath the vines. Jamie lays out samples side by side: soft white chalk that crumbles in the hand, harder fossil-studded limestone from the Côte des Bar that resembles the Kimmeridgian soils of Chablis, colored sands and sandstone, and sticky clays in green, brown and iron-rich red. If soils really shape flavor, this is a place where you should be able to taste it.

The grower and the plots

Jamie's guide in the Marne Valley is Maxime, a grower who works with all three Champagne grapes. He explains how his team reads the two main soils on his land. Sandy plots ripen sooner and give freshness, which suits Chardonnay and Pinot Noir. The clay-limestone, he says, brings out fruit and roundness in Pinot Meunier.

To test the idea, the crew heads to two contrasting sites: the Clos de Cerseuil, a walled plot on clay-limestone, and Les Rieux, on sand. Jamie arrives with a shovel from what he calls his secret laboratory, and the viewer gets a hands-on lesson in how a vineyard looks below the surface.

What happens underground

As the pit deepens, Jamie explains the science in plain language. Clay holds water through winter and releases it slowly in a dry summer, so unirrigated vines neither run wild nor suffer. Its fine particles also hang on to mineral ions such as calcium, magnesium and iron, which the vine needs in tiny amounts. Lower down, the clay turns paler as limestone fragments appear: the argile calcaire that growers prize.

He then sets out two ways soil might reach the glass. Roots take up some minerals passively, so whatever is abundant in the soil can end up in the grapes. And small differences in mineral supply may change how the vine's genes behave, altering the flavor precursors in the grapes that fermentation later unlocks. He also notes that some researchers think climate matters far more than soil, a view he does not share.

The man who tastes the soil

The most remarkable guest is Geoffrey, who makes a bold claim: by breaking open, smelling and even tasting soil samples taken from where the fine roots feed, he can predict how the finished wine will smell and feel in the mouth. On camera, he pulls up cores with an auger and talks through aromas of peas and lentils from living bacteria near the surface, then almond, dried white fruit and citrus from deeper layers.

He also describes how each soil type shows up on the palate, from the saltiness and long finish he links to limestone to the quicker, lighter impression he expects from sand. Before a single glass is poured, he commits to detailed predictions for both plots.

The tasting: will the predictions hold?

The episode closes at the winery, where Maxime pours a finished Champagne from the Clos de Cerseuil and a base wine from Les Rieux. Geoffrey describes what he expects, and Jamie tastes to see whether the wines match the soils they came from.

It is a small trial with just two plots, and Jamie says so. But it gets right to the heart of the terroir debate, and watching a soil profile turn into a tasting note is a rare thing to see. Watch the episode to find out how the wines compare and to hear Jamie's final verdict.