Have you ever seen these crystals in the bottle or glass of your wine?  I once had a server at a restaurant try to explain it as sediment in my white wine.  That’s not what these are.  They are tartrate crystals, also known as wine diamonds.

These wine diamonds are nothing to fear.  They are a natural occurrence that happens from time to time, and are safe to drink.  They are formed from a natural component, called tartaric acid.  Tartaric acid is found in grapes, apricots, apples, avocados, tamarinds, citrus, and bananas.  You can find it in among spices and is commonly used as cream of tartar that can be added to eggs to increase their thickness.

When you see them in wine, it is due to the tartaric acid binding with potassium when the wine is chilled.  They form the white crystals that can stick to the bottom of a cork and can be found in the last pours of a bottle.

These crystals can occur in both red and white wine.  However, they are most commonly found in white wines due to the low temperatures white wine is normally served and stored in.  They can be diminished in the winemaking process with filtering or cold stabilization, where the wine is held just above its freezing temperature for a few weeks.  However, both of these techniques can affect the flavor of the wine.  Plus we’re seeing a trend of winemakers working harder to interfere less with the natural processes of the wine.

So, the next time you see these in your bottle or glass, you’ll know you’ve been graced with wine diamonds.