Yeast selection shapes wine character as winemakers weigh native versus commercial strains

Yeast plays a central role in winemaking, shaping the flavors, aromas, and textures that define each bottle. In conversations with winemakers across the United States and abroad, the choice between using indigenous or commercial yeast strains is often described as one of the most important decisions in the cellar. This decision can influence not only the technical success of fermentation but also the character and complexity of the finished wine.

Yeast are single-celled fungi that have existed for millions of years. Scientists have identified about 1,500 species, but Saccharomyces cerevisiae is by far the most common in winemaking. Within this species, there are hundreds of strains, each with unique properties. Companies like Scott Laboratories supply dozens of these strains to American wineries, offering detailed information about their origins and the specific sensory qualities they can impart to wine. Other yeasts such as Kloeckera, Pichia, and Candida are also present on grape skins and in vineyards. Brettanomyces, another yeast sometimes found in wineries, is known for its ability to add complex flavors—or spoilage—depending on its concentration and management.

For much of wine’s 8,000-year history, winemakers had little control over which yeasts fermented their grapes. The process relied on whatever microorganisms were present on the fruit or in the winery environment. Today, advances in microbiology allow winemakers to select specific yeast strains to achieve desired results. Some choose to add commercial yeast for reliability and predictability, while others prefer to rely on native yeasts for complexity and a sense of place.

Winemakers who favor native yeast often cite complexity and terroir as their main motivations. Adam Lee of Clarice Wine Company in California’s Santa Lucia Highlands says he uses only native yeast because it is both cost-effective and produces more complex wines. He points to research showing that spontaneous fermentations involving multiple yeast strains can create greater depth in flavor. Paul Hobbs, who makes wine in Spain’s Ribeira Sacra region as well as California, uses indigenous yeast for his Godello wines to achieve nuance and expressiveness. He notes that native yeasts ferment more gently than commercial strains, preserving delicate aromas and contributing to a layered palate.

In Argentina’s Uco Valley, Sebastián Zuccardi relies exclusively on native yeast for all his wines. He believes this approach delivers transparency and purity, allowing his Malbecs to reflect their origin at the foot of the Andes mountains. In Napa Valley, Chris Carpenter produces Lokoya Cabernet Sauvignon—one of the world’s most celebrated wines—using almost entirely native yeast. Carpenter says each vineyard’s unique environment creates a distinct set of conditions for fermentation, resulting in wines that truly reflect their site.

Not all winemakers avoid commercial yeast. Lisa Evich at Sebastiani Vineyards and Chateau St. Jean in Sonoma selects specific strains based on her goals for each wine. For Sauvignon Blanc, she chooses a cold-tolerant strain to retain aromatics; for Chardonnay, she uses a strain suited to barrel fermentation; for high-end Cabernet Sauvignon, she picks a robust strain that can handle high alcohol levels and complete fermentation without leaving residual sugar.

Evich acknowledges that native yeast can produce interesting flavors but warns that if populations are too low or weak, fermentation may stall before all sugars are converted to alcohol. This can leave unwanted sweetness in wines intended to be dry. Many winemakers use commercial yeast when necessary—for example, if weather conditions have stressed vines or if there is a risk that native populations will not complete fermentation.

The fundamental role of yeast in winemaking is to convert grape sugars into alcohol and carbon dioxide through fermentation. Each species and strain leaves its own mark on the wine’s flavor profile by producing different byproducts during this process. Winemakers compare this effect to artists painting the same subject: each interpretation is unique.

The choice between native and commercial yeast is ultimately about control versus expression. Some winemakers want consistency year after year; others seek complexity and individuality tied to a specific vineyard or vintage. As technology advances and understanding deepens, winemakers continue to experiment with both approaches—sometimes even blending them—to craft wines that best represent their vision and their land.

Yeast remains one of the most powerful tools available to winemakers today. Its impact on flavor is undeniable, making it an essential part of every bottle produced around the world.