Vinceremos Organic Wine Blog

Tartrate Crystals – what’s that?
It’s a common misconception that the small clear crystals found in wine (mainly white and rosé) are an indication that the wine is faulty. These sugar-like deposits are often found on the under side of the cork but can be found in free suspension in the bottle or settled at the bottom. They are completely harmless crystals which can form when a wine gets cold. Grapes contain both tartaric acid and potassium and under certain cool conditions these can combine to form the crystals which look rather like sugar. Many wineries use a process called ‘cold stabilisation’ which is designed to remove these crystals by lowering the temperature during fermentation. This makes the crystals appear and they are then removed. This process is used purely for appearance purposes and is frowned upon by many people who take their wine drinking very seriously. This is because any process used in wine making can potentially affect the quality of the finished product, so wine purists prefer what they drink to have been treated as little as possible. Although tartrates are completely harmless anyone who has drained a glass of wine to find it contains a mouthful of generally flavourless crunchy crystals lurking within is unlikely to have been impressed. These deposits should be treated in the same way as sediment in red wine and be separated by decanting (see above).