Tartrate crystals:
No reason for complaint

Sooner or later, every wine merchant will face this scenario: an unhappy customer presents a wine cork or a tissue, with the famous small crystals known as tartrates clearly visible. For someone encountering tartrates for the first time, it’s easy to assume that these particles shouldn’t be in the wine, which would indicate a flaw. Similar to the infamous cork taint, except that TCA actually affects the flavor. Tartrates, however, do not alter the taste or quality; they are simply a natural chemical reaction with no impact on the wine.

Many wine drinkers are unaware of this, which can lead to tense situations at the sales counter. Some wine shops are so accommodating that they replace the wine anyway. In the worst-case scenario, you end up drinking the opened bottle yourself. But there is actually no reason to accept or replace a wine with tartrates since they don’t reduce the quality. However, a superficial explanation might only frustrate the customer further, making them feel patronized. It’s much better to communicate on equal terms. Let’s take a closer look at how you can do that.

How tartrate crystals form

First, explain what tartrates are. This can be done succinctly. Tartrates are a compound of minerals and salts like potassium or calcium, as well as tartaric acid. Their interaction is a completely normal process. The chemical result is typically liquid. However, when a wine is cooled, tartrates precipitate and form the small or larger crystals that are then found in the glass or on the cork. Whether liquid or crystalline, it makes no difference to the taste.

Tartrates can form during vinification, primarily in barrels and tanks. But they can also form if wine is transported or stored at cool temperatures. Therefore, tartrates can appear in both young and aged wines and are not necessarily a sign of advanced age, despite what is sometimes assumed.

Tartrate crystals are not the same as sediment

The amount of tartrates that form depends on the level of salts in the wine, often determined by the vineyard and vintage. In some wines, a significant amount of tartrates can form, resembling large crystals, while in others, tartrates are virtually non-existent. Unfortunately, there’s no rule of thumb you can give your customers if they want to avoid tartrates altogether.

Sometimes, customers might also confuse tartrates with sediment, which settles at the bottom of bottles of aged wine. Sediment consists of color pigments and tannins that precipitate over the years and settle at the bottom. Like tartrates, sediment should ideally not be consumed—not because it’s harmful, but because it doesn’t feel pleasant in the mouth. Both are harmless, which is perhaps an important point to share with your customers.

Tartrate crystals as Art for Collectors

Generally, customers are quickly reassured once they understand what tartrates really are. But if you encounter particularly difficult cases, where customers regularly complain and view tartrates negatively, a psychological trick might help. Present tartrates as something positive and beautiful. Some wine merchants keep a collection of wine corks with particularly attractive tartrates on the counter or on display shelves.

This is a great way to show how diverse tartrates can look—some might even resemble small works of art. Some wine merchants take it a step further by providing additional information via a small sign: What type of wine was it? When was it enjoyed? And so on. Some even share these stories directly with their customers. This not only makes wine feel more personal and approachable, but it also shows how unique each bottle can be. Such stories evoke emotions, and suddenly, tartrates leave a positive impression on customers. Instead of dealing with unnecessary complaints, you can now share your passion for wine together.