In the world of winemaking, various additives are employed to enhance a wine’s quality, stability, and flavor. As a sommelier, it is crucial to possess comprehensive knowledge about these additives to effectively guide patrons in their wine selections. Let’s delve into five common wine additives: yeast nutrients, bentonite, enological tannins, dimethyl carbonate, and carbon, shedding light on their purpose, effects, and considerations. In fact, this was one of the questions in the 2023 Master of Wine exam!

Yeast Nutrients

Yeast nutrients are additives used to support the fermentation process. During winemaking, yeasts consume sugar and convert it into alcohol. Yeast nutrients, such as diammonium phosphate (DAP) and yeast hulls, provide essential nitrogen, vitamins, and minerals to promote healthy yeast growth and fermentation. These additives are particularly valuable when dealing with challenging grape musts that lack sufficient nutrients, aiding in the prevention of sluggish or stuck fermentations.

Bentonite

Bentonite is a clay-based fining agent widely used in winemaking to clarify and stabilize wines. It has excellent clarifying properties, removing proteins and unwanted particulates that can cause haze or turbidity. By absorbing and settling these particles, bentonite helps achieve a visually appealing and clear wine. However, it is essential to use bentonite judiciously, as excessive amounts can strip the wine of desirable aroma compounds and affect its structure.

Enological Tannins

Enological tannins are additives derived from grape seeds, skins, or wood. They contribute to wine structure, color stability, and mouthfeel. Tannins can enhance wine aging potential and balanced fruit flavors, especially in wines made from less tannic grape varieties. Careful selection and dosage of enological tannins are crucial, as excessive amounts can lead to excessive astringency or a dominant tannin profile that masks other characteristics.

Dimethyl Carbonate (DMC)

Dimethyl carbonate is a preservative and antimicrobial agent used in winemaking. It helps control microbial spoilage, inhibit unwanted fermentation, and stabilize wines. DMC is particularly effective in preventing refermentation in sweet or semi-sweet wines by inhibiting the activity of residual yeast or bacteria. However, its usage must be strictly regulated, as high concentrations can negatively impact wine aroma and flavor, resulting in a chemical-like character.

Carbon

Carbon, in the form of activated carbon or activated charcoal, is used for wine fining purposes. It aids in the removal of unwanted color compounds, off-flavors, and volatile compounds that can contribute to wine faults or inconsistencies. Carbon is often employed in the treatment of wines affected by smoke taint or other sensory issues. Nonetheless, it is important to exercise caution when using carbon, as excessive contact time or improper dosage can strip desirable compounds and lead to a loss of complexity.

As a sommelier, understanding common wine additives empowers you to navigate the complex world of winemaking and offer valuable insights to patrons. Familiarity with yeast nutrients, bentonite, enological tannins, dimethyl carbonate, and carbon enables you to appreciate their purpose, effects, and potential risks. Remember, while these additives can enhance wine quality and stability, their usage must be well-balanced and carefully monitored to preserve the integrity and unique characteristics of each wine. By continually expanding your knowledge in this area, you enhance your ability to guide wine enthusiasts on their journey of exploration and appreciation.