The Role of Yeast in Winemaking

Yeast plays such a crucial role in winemaking that without its presence, you cannot turn grape juice into wine. The juice simply will not ferment without the help of yeast. While some wild yeast is present in all grapes, this type of yeast is not always predictable and therefore, winemakers must use other types of yeast to ensure that the fermentation process produces favourable results.

What Is Yeast?

Yeast is a single-cell organism that belongs to the fungi group. There are numerous versions of yeast throughout nature and even in our bodies. While certain types of yeast, such as Candida can cause health issues, other forms of yeast, such as the Alsacian yeast strain, play a beneficial role in winemaking and other activities.

How Does Yeast Help With Winemaking?

Yeast helps convert the sugar in grapes into alcohol and carbon dioxide during the fermentation process of winemaking. Manipulation of the yeast helps achieve the winemaker’s desired results. Some winemakers will choose to rely on only the wild yeasts to ferment their wines since the results will produce a product that highly reflects where the grapes were grown. Also, the wine will be different each year and have different complexities. However, you must realise that wild yeasts do not always produce a high enough alcohol content if not supplemented with another type of yeast.

Since the results of wild fermentation can be unpredictable and not easily controlled, many winemakers choose to add commercial yeast, such as the Alsacian yeast strain, to their wines to ensure favourable results in all batches of their wines. Benefits of adding commercial yeasts include:

  • Starting fermentation reliably and quickly
  • Even fermentation throughout the wine with less risk stalling out
  • Effective tolerance of high acid levels in grapes as well any fungicide or mold that might be present
  • Works well in lower temperatures
  • You can choose the best yeast for your specific wine batch

Examples of Commercial Yeast

  • Levuline ALS Yeast is a classic Alsacian yeast strain that is ideal for aromatic wines, such as Sauvignon Blanc, Riesling and Semillon
  • Levuline Synergie Yeast is 30-percent ALS and 70-percent C19, and it is meant to bring about fermentation in rosé and dry white wines
  • Levure Vialatte Ferm R71 Yeast is a robust yeast that helps produce aromatic, fresh rosé and red wines due to the creation of fermentation esters during the fermentation process

For additional facts about the role of yeast in winemaking, consult with Grapeworks Consumables. We sell the above yeasts as well as others along with a wide assortment of quality supplies, additives, equipment and machinery for winemaking and brewing.