In the world of winemaking, the art of fermentation holds a special place. It is during this crucial process that grape juice transforms into wine. Traditionally, winemakers have relied on the power of nature to carry out this magical transformation, utilizing native yeast fermentation. However, in recent history, the use of lab yeast inoculation has gained popularity. Let’s dive into the reasons why some winemakers choose to embrace native yeast fermentation and explore the key differences between this natural approach and lab yeast inoculation.

The Role of Yeast in Fermentation

Yeast, a microscopic fungus, plays a vital role in the winemaking process. It consumes the natural sugars present in grape juice and converts them into alcohol, carbon dioxide, and various flavor compounds. Yeast can shape a wine's aromatic profile, flavor complexity, and overall character.

Native Yeast Fermentation

Native yeast fermentation, also known as spontaneous fermentation, involves allowing the natural yeasts present on grape skins and in the winery environment to initiate the fermentation process. These indigenous yeasts are diverse and unique to the specific vineyard and winery, contributing to the creation of wines with a distinct sense of terroir.

Winemaker Daniel Callan of Slamdance Koöperatieve Wine is a California wine history buff and lover of microbes. When asked why he chose not to inoculate his wine with lab yeast he said, “Native fermentations are just so much more compelling than inoculations. The industrialization of wine brought with it the use of cultured yeast, but when we started inoculating wines we also started sacrificing complexity for convenience. And it’s really at this time that we begin to see a decline in the quality of wine, but also all produce in America.  

The decline in artisan wine mirrored the decline of artisan bread: Wonderbread is cheap, consistent and conveniently pre-sliced. But, it is also almost appallingly simple. Sourdough bread is less-predictable, takes longer to make and requires much more intensive effort and care. It’s also infinitely more rewarding to eat, not to mention to make.

Wine is the same. Utilizing cultured yeast controls and expedites the winemaking process. But it also dumbs it down. I think that part of the rise in the modern-day obsession with phenolics and physiological ripeness was the fact that our wines were getting simple, even boring, as a result of industrialization. Without complexity from fermentation, winemakers started grasping at straws, and tried to get complexity from ripeness instead of process.

There’s also the human element. Anyone can open a packet of freeze dried yeast and dump it into a fermentor.  But the idea of microbial husbandry, of a human being tending to the microbes in a fermentation, being able to interpret their movements and respond to their actions…. That is an artisanal skill, and at its highest level it’s worth celebrating. That’s worth paying for.”

Lab Yeast Inoculation

Lab yeast inoculation involves adding a specific strain of cultured yeast to the grape juice to initiate fermentation. These yeast strains have been isolated, selected, and developed in laboratories to possess desired characteristics such as predictable fermentation kinetics, alcohol tolerance, and the ability to enhance certain flavors.

Benefits of Lab Yeast Inoculation

Consistency: The use of lab-grown yeasts provides winemakers with more control over the fermentation process, allowing for consistency in flavor, aroma, and quality from one vintage to another. This is particularly valuable for large-scale wineries or commercial producers aiming for a consistent style.

Risk Mitigation: Native yeast fermentation carries a higher risk of spoilage due to the presence of unpredictable microorganisms. By using lab-grown yeasts, winemakers can reduce the likelihood of incomplete fermentations or the development of off-flavors, ensuring a more reliable and commercially viable end product.

Time Efficiency: Lab-grown yeasts are known for their robust fermentation activity and ability to complete fermentation more quickly than native yeasts. This time efficiency can be advantageous in commercial winemaking, allowing for faster turnover and increased production.

Conclusion

Both native yeast fermentation and lab yeast inoculation have their place in the winemaking world, each offering distinct advantages and outcomes. Native yeast fermentation embodies the romanticism and connection to nature that many winemakers seek, while lab yeast inoculation provides control and consistency. The decision to use one method over the other depends on the winemaker's philosophy, the desired wine style, and the specific circumstances of each vineyard and winery. Ultimately, both approaches contribute to the rich tapestry of wines we enjoy, ensuring that the world of wine remains diverse and captivating for wine enthusiasts around the globe.