An ancient black grape variety, it represents a rare fragment of Umbrian biodiversity. Its roots date back to the dawn of time: probably of Greek origin, it was already cultivated by the Etruscans and cited by Pliny the Elder as "Tudernis," before being identified for centuries with the names Greco Nero. Due to its extremely low and unpredictable yield, incompatible with the post-war industrial logic, it risked extinction permanently.

Recovered by the Zazzera winery through the study of old military maps, word of mouth, and a fortunate discovery, Grero has been reborn thanks to the discovery of centuries-old ungrafted vines that survived phylloxera.