Ever drink a glass of wine and find little crystals at the bottom? These are 'wine diamonds', and they are not a sign of bad quality – they have been helping to preserve your wine! Wine diamonds are potassium bitartrate crystals (or cream of tartar) and form when wine is chilled. During the winemaking process they naturally accumulate on the sides of fermentation tanks, and do not in any way mean that there’s a problem with your wine. In fact, they help lower the pH, making a hostile environment for many types of bacteria that can spoil wine! This is an indication that your wine was made very naturally, without excessive filtration and stabilisation.