César Márquez Pérez represents the ninth generation of a family rooted in Valtuille de Abajo since 1752, the date of the earliest surviving property documents. His family founded Castro Ventosa in 1990, but César took his own path: he studied oenology in Requena, spent seven years learning with his uncle Raúl Pérez at La Vizcaína (Bierzo) and completed a harvest with the Michelini brothers in Valle de Uco before launching his own project in 2015 with just over 1,300 bottles across four single-parcel wines. In 2017 he also became technical director of Castro Ventosa, running both projects in parallel.

César Márquez's Bierzo is a collection of micro-parcels of old vines — 60 to 120 years old, some ungrafted centenarians — farmed organically and sourced from elderly growers who can no longer work alone. The dominant variety is Mencía, co-planted with Garnacha Tintorera and native white varieties. Each parcel has its own logic: El Rapolao is a north-northeast slope at 500 m in Valtuille on iron-rich clay; Sufreiral, in Toral de los Vados at 620 m, sits on limestone — exceptionally rare in the Bierzo — which gives it a minerality and texture unmatched in the appellation; Pico Ferreira, in Corullón at 710 m on steep slate and schist, is the most extreme parcel and the flagship wine. The whites — La Salvación and El Val — come from century-old Godello in Valtuille.

In the cellar, transparency of origin is the guiding principle: spontaneous fermentation, partial whole-bunch inclusion (up to 65% depending on parcel and vintage), long macerations of 35 to 60 days, twelve months in used 500-litre French barrels and gravity bottling with no heavy filtration. The result is wines of 12.5–13.5% alcohol — fresh, tense and built to age. Pico Ferreira 2024 earned 100 points from Guía Peñín — the first perfect score ever given to a Bierzo wine in that guide — and 96 from Wine Advocate; El Val 2023 reached 96 points in both publications. Tim Atkin MW named him Bierzo Winemaker of the Year 2025, and Decanter places him among Spain's ten best winemakers.