Found crystals in your bottle? Understanding wine tartrates
17 October 2026 · Vikipedia
Picture the scene. The wine arrives, you pour a glass and someone points to a few crystals at the bottom of the bottle.
“That’s gone bad, hasn’t it?”
The conversation about dinner stops. Suddenly everyone is a quality inspector. The person choosing by the label a minute ago has just been promoted to laboratory director.
Let’s take a breath.
What might be in that bottle?
One of the most common crystalline deposits is potassium bitartrate, a type of tartrate. It forms from components present in grapes and wine. These crystals do not themselves damage wine quality.
The name sounds rather more intimidating than the explanation. “Tartrates” will do. There is no exam before the main course.
Stabilisation before bottling helps prevent these crystals appearing later.
So every deposit is normal?
Not quite. Not every deposit is a tartrate. Identifying an unknown one may require laboratory analysis; a photograph cannot establish exactly what a bottle contains.
That distinction matters. Reassuring someone without knowing would be just as unprofessional as condemning the wine without knowing.
If it happens, ask the person serving it or the winery. “What is this deposit?” is a much more useful question than “This wine is bad.”
The point is to understand what is in your glass. Dinner already involves enough decisions without adding a trial with no evidence.
Sources and review
2026-10-17 · Vikipedia