Sancerre and Pouilly-Fumé. Sauvignon Blanc at its source.

The Upper Loire and its climate

Far from the Atlantic, the eastern Loire, often called the Upper Loire or Central Vineyards, has a more continental climate than the rest of the valley. It is still a cool region, but with hot summers and cold winters. Two grapes dominate: Sauvignon Blanc and Pinot Noir.

Sauvignon Blanc, whose name may come from the French sauvage, or wild, is sometimes dismissed as simple and loud. Peter Richards happily admits he loves it, and the episode argues that the more structured, intense styles, whether from single vineyards or aged in oak, can age remarkably well. Paz Levinson recalls a decades-old Sancerre that still tasted fresh and vibrant.

Soils on the label: Caillottes, Terres Blanches and Silex

Paz brings a box of local stones to explain three soil terms you will often see on Loire labels. Caillottes are stony limestone soils. Terres Blanches are white clay and limestone soils, rich in fossil shells. Silex is flint, mixed with clay and limestone.

Nobody can literally taste rocks in a wine, but producers credit certain soils with certain effects, and many Loire Sauvignons do share a mineral, smoky or gunflint character. The French call it pierre à fusil. Watch Paz strike two flints together so Peter can smell that struck-match aroma for himself.

Sancerre, Pouilly-Fumé and their neighbors

Sancerre lies on the left bank of the Loire and covers 14 communes of hills and valleys. It makes white, rosé and red. Sauvignon Blanc is queen, from fresh and fruity to complex, single-vineyard and sometimes oaked wines. Before phylloxera, Sancerre was mostly a red-wine area; today about a fifth of its vineyards are Pinot Noir, and Sancerre Rouge must be 100% Pinot Noir.

Pouilly-Fumé, on the flatter right bank around Pouilly-sur-Loire, makes only white wine from Sauvignon Blanc, known locally as Blanc Fumé. Do not confuse it with Pouilly-Fuissé, a Chardonnay appellation in southern Burgundy.

Nearby, Quincy makes softer, white-only wines on sandy river terraces. Reuilly adds Pinot Noir reds and a rare pale rosé from Pinot Gris. Menetou-Salon offers Sauvignon Blanc and Pinot Noir from similar terroir to Sancerre, often at lower prices.

The acidity experiment

Acidity is one of the most fundamental traits of wine, and the hosts make it visible with red cabbage juice, a natural pH indicator. The pH scale runs from 0 to 14: the lower the number, the more acidic the liquid, and most wines sit at about 3 to 4. Lemon juice and floor cleaner turn the purple juice two very different colors.

Then comes the real question: does a dry white wine or a sweet wine contain more acid? The answer surprises many learners, and it explains why balance between sugar and acidity matters so much. Higher acidity also helps wines stay stable and age well, while wines that are too high in pH can lack freshness and keep less well. It is a simple experiment you can repeat in your own kitchen.

Food pairings and blind tastings

The pairings are simple enough to try at home. A Sancerre Grande Réserve from Henri Bourgeois, from Chavignol, meets the village's other famous product, Crottin de Chavignol goat cheese, on toast with honey and walnut. Later, grilled shiitake mushrooms and prawns with rosemary and lemon zest show how a light, low-tannin red can work with seafood.

There is plenty of blind tasting too. Peter is challenged to tell a Sancerre from a Pouilly-Fumé side by side, and each host is given a mystery wine to describe and identify. See how they work from color and aroma to structure and quality, and find out whether they get it right.