Significance of Yeast and Additives in Winemaking

When it comes to winemaking, yeast and additives are significant ingredients for proper fermentation. Because food products such as beer and wine have volatile structure, advanced methods are utilized for stabilization. And with wine, there are various additives that are used; some that date back for centuries.

Additives are used to stabilize the wine and not to adulterate. In fact, wines have a much longer shelf life when they are stable.


Yeast is the key ingredient that transforms grape juice into wine. It is a one-cell microorganism that eats up sugar and makes alcohol. Yeast is also what gives wine it body, aroma, flavor and mouthfeel. As well, a healthy and active yeast population helps prevent spoilage caused by other micro-organisms. In fact, yeast microorganisms (Saccharomyces cerevisiae) are quite aggressive when compared to other microbes.

There are also different types of yeast that greatly affect the flavor of wine. Cultured yeast is typically customized to suit the needs of a winemaker. It is the yeast often used for “New World” wines. Ambient yeast is an older traditional fare and is naturally present in wine cellars such as the equipment. As well, it is not as effective at high sugar levels and will often die before the preferred alcohol level is reached. There are also various yeast strains. Each strain will have different responses to sugar levels which attributes to the various types of wine.

Tannin Powder

Tannin powder is used to enrich the astringency and structure for varietals that have low levels of tannins. It is generally a combination of grape skins and seeds, chestnuts, oak and nutgall or excrescence (a tiny swelling tree branch bark). Tannin powder adds character while keeping the clarity and quality of the wine.

Potassium Sorbate

Potassium sorbate (PS210) or wine stabilizer is used to protect the wine from bacteria. In sweet wine, it is frequently used to inhibit further fermentation once bottled. As well, the use of potassium sorbate is highly recommended for wines that are sweetened or are naturally sweet after fermentation.

Oftentimes, Potassium Metabisulfite or Campden are also added to help release the potassium sorbate in the wine.

Sulfur Dioxide or Sulfites

Sulfur dioxide or sulfites are an anti-microbial agent often used to preserve and safeguard the veracity of the wine. It has a variety of characteristic such as killing ghastly bacteria and microbes, stopping fermentation and protecting the wine flavor.