What are those crystal-like pieces floating in the bottom of my wine? What are tartrates?

What are those crystal-like pieces floating in the bottom of my wine? What are tartrates?

Q: I've just opened a glass of wine. I'm quite excited, but wait...when I hold the little bottle up to the light, I come to find some small, shard-like white or red crystals tumbling around inside. What the %&$@! is in my wine! 

By: Tyler Kennedy 

Tartrates Wine


Immediately you begin to wonder if there’s something wrong with the wine you were just seconds away from drinking with reckless abandon. Now you’re not so sure. You’re shook, and this discovery has given you pause. What in the world is in there? Should I still drink it?!


The short answer: there is nothing wrong and you should absolutely drink that special little glass of wine.


Though the reason that they’re there in the first place is pretty neat. You see, three main acids exist in the grapes used to make wine: malic acid, citric acid and tartaric acid. Of those three, it’s the tartaric acid that’s responsible for the refreshing tartness we get in wine and the same acid that creates those pretty little crystals.


While malic acid is mostly converted to the more mellow and soft lactic acid during fermentation (malolactic fermentation is something we can get into later,) tartaric acid stays the course and maintains its chemical consistency. Tartaric acid is crucial in helping maintain the wine’s pH levels and protect it from spoiling.


One problem: it doesn’t always like to stay dissolved in the wine. At risk of getting even nerdier, the tartaric acid compound is very susceptible to fluctuations in temperatures. If the wine had to travel through a frozen tundra en route to the consumer, chances are the acid compound actually solidified and fell out of the solution. That is what you’re seeing floating around the bottom of your glass or stuck to the bottom of your cork, harmless tartaric acid in its solid form.


Think about it this way, if you don’t see the crystals that means the wine was kept at a consistent temperature, but that compound is still in the wine, and you’re still consuming it. If that same acid solidifies in your wine, and you happen to swallow it, you’re consuming the exact same thing. The perfect comparison here is that it’s like water that’s been turned to ice. Ice is still water. Still harmless, just in a different form.


The higher quality your bottle of wine is, the more likely you are to see those “flavor savers” floating around. At the lower end of the wine spectrum the wines are often ‘cold stabilized’ in order to filter the crystals out. This is done by bringing the wines to near freezing temperatures and letting the tartrates solidify and fall to the bottom to be filtered. This ensures a wine’s clarity but at the cost of the wine’s flavor, aroma and ability to age.


So, if you find some little shards of crystal floating around in your next wine tube, don’t fret, it’s a good thing. That means that you can guarantee that the wine was not over-processed and has all of its beautiful subtleties intact. Très chic!

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Good info. I make 250 gallons of wine which almost never changes temp as long as it’s in my wine cellar.

Kerry roberts

Very interesting! I love learning new things about the wine. Thank you so much for sharing!

Carol C Dukes

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