Sometimes, as you near the end of a bottle of white or rosé wine there appears to be what looks like crystals of glass or sugar in the bottom. What is it and should I be worried?
The short answer is no! These are tartrate crystals and are totally ok. Tiny crystalline deposits that resemble sugar or glass, they appear when potassium and tartaric acid bind together. These acids are naturally found in wine and are completely harmless. You’re less likely to see tartrate crystals in red wines as the levels of tartaric acid are generally lower and reds are normally subject to longer periods of ageing.
Tartrate crystals appear when wines are kept too cold and industrial producers that are making mass market wines will ‘cold stabilise’ their wines to stop tartrates from forming. The appearance of tartrate crystals in your wine is actually an indication that it has not been over-processed.
