Köstlich Edelsüße Schätze
Crystals in Wine
Herbstlich
CRYSTALS IN WINE
To get straight to the point: tartrate crystals in wine, known as “Weinstein” in German, are completely harmless to health and do not influence the taste of a wine in any way. Nor are they a sign of poor wine quality; on the contrary, they are a natural product of minerals and fruit acid in wine.
How do crystals develop in wine? Tartrate crystals form when the natural potassium or calcium in wine binds with tartaric acid. Basically, it is present in all wine in its soluble form. There are several reasons why, when the minerals and tartaric acidity combine, clear or white or amber-colored crystals develop that are visible to the eye. Storing wines at a low temperature is one possible cause. Whether, and how many, crystals form also depends on vintage and alcohol content.
Not a question of age Some tartrate crystals already precipitate during fermentation and barrel aging. The frequent assumption that crystals only form in older wines is simply not true. What can change with age, though, is the size of the crystals. In bottles that have been stored in the same place for a long time, the individual crystals can combine into larger units.
A different type of “crystal” In high-quality wines produced from especially ripe or overripe grapes, such as Auslese, Beerenauslese, Trockenbeerenauslese or Eiswein, there are occasionally very fine, almost dust-like particles. These are not tartrate crystals per se, but rather natural calcium salts that have precipitated due to higher storage temperatures. In addition, so-called deposits often develop in fullbodied, tannic red wines over the years. This rather powdery, dark-colored sediment consists of tannins and pigments that bind and sink to the bottom of a bottle with increasing maturity. Crystals do not harm a wine in any way and are not indicators of a wine’s quality. Neither crystals nor deposits are welcome in the glass. Therefore, it’s worth the effort to pour wines very carefully to prevent them from ever leaving the bottle. With red wines, decanting prior to serving helps – preferably in front of a source of light to ensure that the deposit remains behind.