WHAT IS WILD YEAST FERMENTATION IN WINE?

Fermentation is what turns grape juice into wine. Yeast consumes sugar and produces alcohol and CO2. Simple enough. But the yeast you use makes an enormous difference to the wine you end up with.

WHAT IS THE DIFFERENCE BETWEEN WILD YEAST AND COMMERCIAL YEAST?

Commercial yeasts are laboratory-cultivated strains selected for predictability and reliability. They ferment consistently, at controlled temperatures, and produce wine with a predictable flavour profile. Most mass-produced wine uses commercial yeasts.

Wild yeasts — also called ambient or indigenous yeasts — are the naturally occurring microorganisms present in the vineyard and the winery. They vary from place to place and year to year, and they produce more complex, variable fermentations.

WHY DO LOW INTERVENTION PRODUCERS USE WILD YEAST?

Wild yeast fermentation is one of the defining characteristics of natural and low intervention winemaking. Producers who avoid adding commercial yeasts do so because they believe wild fermentation produces more expressive, terroir-driven wines that genuinely reflect their origin.

The process is riskier — wild fermentations can be slower, less predictable, and occasionally fail. But when it works, the results can be extraordinary.

WILD YEAST AT LOCO WINES

All of our producers use wild yeast fermentation. Marc and Miriam in Penedès ferment Arriba with wild yeasts before bottling mid-fermentation for natural bubbles. The Hoch family use wild yeasts across all four of their Loco wines. This is not just a technique — it is a philosophy about letting nature do the work. Shop the range at locowines.co.uk.