Diolle

Between tradition and the courage to do things differently.

Cave des Bernunes was founded in 1987 by Nicolas and Nadine Zufferey – back then, winemaking still took place in the cellar of the family home. Today, the family tends around nine hectares of vines around Sierre and cultivates some 15 different grape varieties. With Lucie, a qualified oenologist, and Luca, a winegrower and cellar master, the next generation is now working alongside them in the business.

In the vineyard, the family focuses on low yields, grass-covered plots and the gentlest possible tillage – some vineyards are even worked using horses. In the cellar, they combine tradition with a spirit of experimentation: new methods are first tried out in small batches before being incorporated into production.

And one surprising detail shows that Nicolas Zufferey is not afraid of unconventional decisions: he was one of the first Valais winemakers to consistently opt for screw caps. Since 2021, Cave des Bernunes has even been using them to seal all its wines – white and red, tank-aged and barrique-aged alike. For Nicolas, this is not a question of prestige, but of reliable wine quality and clean ageing.

The Diolle, in particular, is therefore a perfect match for this winery: an almost extinct Valais grape variety meets a family that does not simply preserve tradition, but is prepared to develop it further.

Diolle was a grape variety from Valais, first mentioned in the Sion region in 1654 under the dialect name ‘Jiolaz’. It was considered to be very high in acidity, with a rather neutral character, and prone to rot. This is probably why the variety disappeared – 1903 is regarded as the year of its demise. Or so it seemed. However, in 2005, the late winegrower Germain Héritier from Granois contacted the ‘grape variety expert’ José Vouillamoz: he had discovered two unknown vines in his vineyard and wanted to know what variety they might be. The DNA profile did not match any known grape variety. A ‘paternity test’ then revealed that it was a descendant of ‘Rèze’. Further research by José Vouillamoz subsequently established beyond doubt that these two vines represented the ‘Diolle’ variety, which had been believed to be extinct. 

Genetic analyses revealed another surprise: Diolle is a natural offspring of the old Valais grape variety Rèze; the other parent remains unknown to this day. It thus literally embodies a piece of Valais wine history that has not yet been fully unravelled.

But the story is only just getting really exciting. José Vouillamoz was convinced of the potential of this rediscovered variety and managed to secure the cooperation of Didier Joris, a leading figure in Valais viticulture. In 2013, a new Diolle vineyard was planted on 3 ares in Chamoson. However, the first attempt to revive the Diolle variety failed: the choice of rootstock proved to be poor, and all the vines died. On the second attempt, however – a new planting in 2015 – the revival became a reality. In 2017, 8 kg of grapes were harvested, yielding 6 bottles of wine. And 2018 saw the first proper harvest – 144 bottles of wine from the revived grape variety were produced.

And ‘rare’ here really does mean rare: in 2023, a mere 0.4 hectares of Diolle were registered across the whole of Valais. By way of comparison, that is not even the area of a single football pitch.

Learn more about this grape variety