Old Riesling or young? The Mosel puts the question to the test.

Why ask the question in the Mosel

Riesling has a reputation for extremely long-lived wines, yet Jamie points out that it is delicious young, in middle age and old. That makes the Mosel the ideal place to compare. He also raises a wider point: red wines used to be tannic and needed long cellaring, but today most people lack space to store wine and restaurants rarely cellar it. So where do old wines fit now?

He wonders whether fine wine has become something bought young and stored in a warehouse as an investment, rather than something people actually open and enjoy. To find out what age really does to a wine, he combines a winemaker's lifetime of experience, a chemist's lab bench and a very informal blind tasting. Each approach gives a different angle, and together they make for one of the richest episodes in the series.

Ernst Loosen and the Würzgarten

Jamie's first host is Ernst Loosen, known as Ernie, who drinks his own wines and his Bordeaux and Burgundy only when mature. He believes old wine has something magic, but that people need experience to enjoy it, because wines pass from primary to secondary to tertiary aromas, a bit like awkward teenagers becoming adults.

Ernie pours two Ürziger Würzgarten Spätlese wines from the same vineyard, 30 years apart, and the difference in color and aroma is striking. In the vineyard itself, he explains why steep, south-facing slopes at lower elevation make great sites, and why the Würzgarten, or spice garden, stands out on weathered red volcanic soil in a valley mostly known for slate. His grandfather's advice was to start drinking Mosel Riesling at vintage plus ten.

In the cellar, Ernie shows large German oak foudres where wines ferment with native yeasts and rest on their lees for years without stirring, in one case eight years, followed by more time in bottle before release. It is a method his great-grandfather used, and Jamie tastes a 2017 that spent eight years on its lees to see how fresh such a wine can stay.

The chemistry of aging with Dr. Ulrich Fischer

At the DLR Rheinpfalz wine campus in Neustadt, flavor chemist Dr. Ulrich Fischer explains what happens in the bottle, describing it as a kind of chemical balance in which some compounds fade while others emerge. Fruity esters made by yeast during fermentation slowly break down in the wine's acidity, faster in warm storage. Meanwhile grape-derived floral and spicy compounds called monoterpenes, held in an odorless form bound to sugar, are gradually released, adding complexity.

Oxygen changes things again. Floral linalool can turn into alpha-terpineol, which has little smell, and acetaldehyde can bring sherry-like notes. In a lab demonstration, Ulrich adds acetaldehyde to a rosé to show how color pigments join together and deepen, then uses sulfur dioxide to bleach the color, illustrating why SO2 is wine's long-standing guardian.

A trained panel and a blind challenge

Ulrich's sensory panel of trained judges then profiles a 21-year-old dry Pinot Blanc Spätlese from the Pfalz, measuring intensity rather than personal liking. He explains where the honey, nut, tea and dried apricot notes of an older white come from.

For a more subjective test, Ernie gathers six young wine drinkers for a blind preference tasting of young and older Würzgarten Rieslings, dry and fruity. He and Jamie each bet on which glass the group will choose, and the outcome surprised at least one of them. Watch the episode to see how the votes fall and to hear Jamie's final answer.

Go furtherWant to taste along? Find Dr. Loosen’s wines and where to buy them near you on Wine-Searcher. To explore the estates, vineyards and wines of the Mosel and Germany further, the wein.plus wine guide is a great resource.