What is yeast, Natural Wine and Winemaking - primalwine.com
Natural Winemaking

What is yeast?

• Yeast is a single-cell fungi essential to alcoholic fermentation

• It converts the sugar in grape juice (fruit juice) into alcohol and carbon dioxide (CO2)

• There can be ambient yeast or cultured yeast

Ambient yeast

• Also known as native yeast or wild yeast, it’s found in the winery or vineyard

• Ambient yeast is peculiar to the environment where it lives (more on terroir soon)

• There can be several yeast populations in a vineyard/winery

Cultured yeast

Also known as commercial yeast or selected yeast

Lab-produced strains of yeast with specific characteristics and aromas

Can be made and sold at scale based on market needs

Yeast in Natural Wine and Winemaking

• Natural winemakers prefer not to inoculate cultured yeast

• That’s why we speak about spontaneous / wild fermentation with ambient / native yeast

• Saccharomyces cerevisiae is the most common yeast responsible for alcoholic fermentation