Gunderloch's Pettenthal vineyard, part of the prestigious Nierstein district of Rheinhessen, sits on red sandstone and volcanic soils that bestow earthy minerality and drainage. The east-facing slope captures morning sun whilst avoiding excessive afternoon heat. Gunderloch practises sustainable viticulture with selective harvesting. The 2022 vintage in Rheinhessen experienced mild spring conditions followed by a warm, dry summer; moderate September rain refreshed the vines, delivering ripe but balanced fruit with good acidity retention—ideal for Grosses Gewächs standards.

The 2022 Pettenthal Riesling was harvested at full ripeness for the Grosses Gewächs designation, which mandates dry-wine production. Gentle whole-cluster pressing preceded cool-temperature fermentation in stainless steel, preserving aromatic expression and fresh acidity. Spontaneous or cultured fermentation was managed to dryness, with the wine maintaining mineral purity. Maturation occurred on fine lees for several months without oak. The wine was lightly fined and filtered before bottling, ensuring clarity and stability.