Have you ever come across what appears to be white flakes floating in your wine bottle? Did you assume that this snow globe appearance somehow meant the wine was defective or spoiled?

What you have probably seen are tartaric crystals, commonly known as “wine diamonds” or Weinstein (“wine stone”) in German-speaking countries. So do these wine diamonds indicate a bad bottle of wine?

Opinions on this subject are divided and the reason is simple: you have bought an impeccable wine, but you have not bought an aesthetically impeccable wine. Depending on where you are from, this may matter to you more or less.

The American wine drinker is not used to finding wine diamonds in their bottles. Here, most wines undergo a cold stabilization process, which is when a wine is chilled before bottling so that the white flakes, called crystallized tartaric acid, “fall off” and can be separated from the wine. But at what price beauty? Cold stabilization influences the balance and flavor of a wine: as some winemakers say, the wine is actually breaking down, and rapid cooling changes the colloidal structure of the wine. One might call it a clear case of style over substance.

There is another interesting correlation between wine pits and the quality of a wine: the longer grapes hang on the vine (colloquially called “hang time”), the more wine acid will accumulate in the grape, and it is this acid from the wine which is the building block of wine diamonds. Also, the longer the wine is allowed to ferment, the less wine diamonds will fall out during fermentation, but more will accumulate later in the bottle.

In other words, wine diamonds are an indicator that the grapes have been ripening for a long time and that the winemaker fermented the wine slowly and very carefully. Both are important precursors to the production of high quality wines.

Hans Gsellmann, chief winemaker at the famous Gsellmann & Gsellmann winery in Austria, explains it this way: “Part of the acid in the grapes is tartrates, also known as salt. As the wine matures, these tartaric acid crystals It’s a natural process that a wine will work its way to the peak of its making.When you see these flakes on the bottom of the bottle or on the cork, you can be pretty sure you’re opening the wine at the right time. You must consider yourself lucky.”

Wine aficionados in the Old World are known to look to bottles with wine stones as a sign of quality: it shows that the wine has not been stripped of its structure through unnatural cooling, and is a sign of a poor wine. well matured. Perhaps it is due to the long history of winemaking in these countries that people have become accustomed to wine stones and seem to accept them. At least they seem to know that, if anything, the wine diamonds will have added roundness to the wine by subtracting some of the acid.

There’s a new technology coming out of France that promises to sidestep the whole colloidal problem: electrodialysis. But until every notable winery has bought one of these fancy French machines (and that will certainly be a few decades), this rule of thumb applies: cold stabilization is like throwing out the baby with the bathwater. You may be left with an aesthetically flawless wine, but you are also left with a lesser wine.