Stag’s Leap Wine Cellars
Sediment: Down to the bottom of the bottle
From time to time we receive questions about “sediment” or “crystals” that collect at the bottom of a bottle as a wine ages. This topic is as old as the wine making process itself. Ancient Middle Eastern texts mention sediment in conjunction with winemaking, and the Romans practiced the art of Oenomancy, a form of divination using the sediment, colors and patterns left in the bowl of wine to interpret messages from Bacchus, the God of wine. The priestess, known as Bacchante, would pour the wine as an offering and then interpret the remains including considering the taste and aroma, which might make her one of the earliest wine critics on record.
Chemically speaking, sediment is a natural byproduct of the fermentation process and the aging of a wine. Wine is a complex matrix with particles of different sizes and shapes interacting in a dynamic way. These interactions occur at the molecular level all the time and at first appear to be invisible to the naked eye. Time, storage temperature, and storage conditions all influence the speed of the chemical interactions within the wine matrix and create macromolecules changes in the liquid. When the difference between the density of these macromolecules is greater than the density of the liquid particles will “drop“ out of the solution and we are able to see the result at the bottom of a barrel, tank, or bottle. The most common wine sediments found are grape derived compounds such as potassium bitartrate (you commonly know this as cream of tartar used in baking), tannins, and color pigments. Proteins and polysaccharides, derived both from the grapes and the microorganisms used in the winemaking process also contribute to the sediment. Sometimes tiny, colorless crystals in white wine, or purplish crystals in red wine, form in the bottom of the bottle. Winemakers affectionately call these crystals “wine diamonds.”
Throughout the winemaking process steps such as racking, fining, cold stabilization or filtration may be used to clarify and remove the particles suspended in a wine. Nicki Pruss, winemaker at Stag’s Leap Wine Cellars, carefully considers the choices at every step of the process to make sure the wine that results meets the highest standards without compromising the wine’s complexity. As you can see, formation of sediment is a natural process and not indicative of lesser quality. In fact many connoisseurs are happy to find those “wine diamonds & rubies” at the bottom of the bottle.
Although wine sediment is edible and non-toxic, the texture of the sediment, be it chunky, or fine and silty, can detract from your enjoyment of a wine if it is poured into your glass. We recommend gentle handling of the bottle to keep from redistributing the sediment throughout the wine and standing bottles upright in a cool, vibration-free space for 24-48 hours before serving. This allows any sediment to settle to the bottom before you pour or decant the wine. To decant, it's best to hold a flashlight, or candle for the traditionalists in our midst, below the neck at the shoulder of a bottle to help see where the clear wine stops and the sediment begins as you pour the wine. This is most helpful when pouring red wine out of dark colored bottles. You can also purchase funnels for decanting that include a fine mesh strainer just for this purpose but be careful not to splash an older wine or you can lose some of the more delicate aromas. Now, the next time you get down to the bottom of the bottle, you’ll know how to handle sediment like a wine professional and enjoy the wine that is awaiting your discovery.
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