Ever taken a sip of wine and noticed something unexpectedly…crunchy in your mouth? Don't panic…, probably you are drinking a high quality wine!
Those little diamonds in your wine are potassium bitartrate and are harmless by-products of the wines. When exposed to cold temperatures, the tartaric acid naturally found in grapes binds with potassium to form a compound called potassium bitartrate.
Winemakers can remove them through a process called cold stabilisation but this process puts the wine under a lot of stress and can affect its quality. In plain words, the cold stabilisation process involve to keep the wine from -4C and -8C for up to 8 days and then racked off. There are even more intruding processes, such as the contact one or the usage of gum Arabic and Metatartraric Acid, but those processes are for very low quality wines.
Once formed they’ll never disappear, but they won’t affect the aroma, taste or quality of the wine. If you find them unsightly, you can either decant the wine before serving or filter it through a muslin cloth. For me some sentiment on aged wine is a mark of quality, since the wine has not been overly manipulated.
Vinifera has adopted the philosophy of Monsieur de Villaine at Romanee-Conti, who believed that the winemaker was no more than an intermediary between the soil and the wine and that he should interfere as little as possible.
As our grandma was always saying cheerfully: "Diamonds Are the Wine Lover’s Best Friend"