By Justin Taylor
One of the most widely used tools in the wine industry today has been a production additive long before wine makers completely understood its properties. For hundreds of years wine has contained and been treated with sulfur dioxide to produce a product worthy of age and future consumption. Today it is referred to as Meta, KMS, Potassium Metabisulfite, all of which can be considered sources for the desired end product, Sulfites.
Sulfites are first and foremost a natural by-product of the fermentation process. The form used mostly during the cellar activities of winemaking is a powder easily dissolved in water to treat juice and wine. Elemental sulfur, occurring naturally in highly volcanic regions of the world, can also be burned inside barrels once emptied to create a sterile and oxygen free environment to suppress microbes from growing. As a wine nears completion for packaging, sulfur dioxide is added in very small amounts to ensure freshness once the wine is bottled and ready for aging. Red wines tend to have lower levels of sulfites than white wine, and some of the richest white dessert wines in the world are permitted the highest levels of total sulfites in suspension. These outline the majority of the desired uses of sulfites in the wine industry today.
A large misconception surrounds the presence and use of sulfites in the fresh food and beverage industry that has largely been pinned on this preservative. The allergen component of sulfites is mostly tied to an asthmatic reaction, and not related to headaches. Everything from veggies on a salad bar to dried fruits have been known to receive treatments with sulfites in order to preserve freshness for the end consumer. Winery technology and industry knowledge today have limited the need for high levels of sulfites present in the final wine, allowing the end consumer to receive a wine that is not only true to character but able to be aged slowly under proper cellar conditions.
The answer to the most recent Wine and Vine trivia is depending on care, barrels can last for decades. Barrels used in the Solera system of Sherry production can be used for over 100 years, while wines desiring a strong oak profile only benefit from 3 or 4 year old barrels. Trivia for next issue: What plant based compound provides wines with astringency and color retention?
Justin Taylor is Assistant Wine Maker at Burntshirt Vineyards, Hendersonville, NC.