The Rheingau's sister Riesling region west of Koblenz, with the Middle Mosel's steep slate slopes around Bernkastel, Wehlen and Piesport producing featherlight, slatey Riesling at a sharper register than the fuller Rheingau wines.
Pours: Mosel Riesling Kabinett, Mosel Riesling Spaetlese, Mosel Riesling Grosses Gewaechs
Tip: Make it an overnight rather than a day; the Middle Mosel sundial villages need two or three estate stops to read the slate spectrum.
Directly across the Rhine from the Rheingau, Rheinhessen's Roter Hang slopes between Nierstein and Nackenheim make Germany's other red-slate Riesling, with the urban anchor of Mainz at its eastern edge.
Pours: Rheinhessen Riesling trocken, Niersteiner Roter Hang Riesling, Rheinhessen Spaetburgunder
Tip: Take the Bingen-to-Ruedesheim car ferry across the Rhine; it puts the eastern Roter Hang within a 30-minute drive of any Rheingau base.
Immediately west of the Rheingau down the Rhine, the Mittelrhein runs the Bacharach-Loreley stretch through the UNESCO Upper Middle Rhine Valley, with steep slate vineyards on both banks of the river.
Pours: Mittelrhein Riesling trocken, Bacharacher Riesling, Mittelrhein Spaetburgunder
Tip: Take the boat from Ruedesheim past the Loreley to Bacharach for a vineyard-from-the-river view, then taste at a Bacharach Riesling estate on arrival.
The Nahe runs west into Bad Kreuznach with volcanic, slate and porphyry soils, making Riesling now ranked beside the Mosel and Rheingau. Schlossboeckelheim Kupfergrube and the Niederhaeuser sites are the headline GG estates.
Pours: Nahe Riesling trocken, Schlossboeckelheim Kupfergrube Riesling, Nahe Spaetburgunder
Tip: The Nahe's varied soils make for striking side-by-side tasting; group three estates in one afternoon rather than spreading across the valley.
South of Rheinhessen along the Deutsche Weinstrasse, the Pfalz's Mittelhaardt towns Deidesheim, Forst and Ruppertsberg make fuller, riper Riesling and a serious slice of German Pinot Noir and Pinot Blanc.
Pours: Pfalz Riesling trocken, Pfalz Spaetburgunder, Pfalz Weissburgunder
Tip: Pair a Deidesheim Riesling tasting with a Pfalz Pinot Noir stop in Forst or Ruppertsberg; the region runs hotter than the Rheingau and the styles read differently.
Southeast of the Rheingau on the warm sandstone slopes between Heppenheim and Darmstadt, the Hessische Bergstrasse covers around 460 hectares across 13 German wine-growing regions, with Bensheim as the anchor town.
Pours: Hessische Bergstrasse Riesling trocken, Bergstrasse Weissburgunder, Bergstrasse Spaetburgunder
Tip: The Hessische Bergstrasse is small enough for a real half-day; combine Bensheim's Staatsweingut with a Heppenheim village tasting.