The Gritty Truth: Why is there Sediment in my Wine?


Have you ever poured yourself a nice glass of wine just to notice something gritty or sand-like has suddenly invaded your wine and is now swishing around unpleasantly in your mouth?

If you’re an avid wine drinker like the majority of us in our office, or if you receive any of our wine of the month club shipments, you’ve experienced the sensation mentioned above at least a handful of times. If you’ve only recently encountered sediment in your glass, don’t worry, there is nothing wrong with your wine! In fact sediment is a completely natural occurrence in red and white wine, and can actually be a sign that you’ve gotten yourself a high quality bottle! But we’ll get to that.

Technically speaking, sediment is also called “wine dregs” - but before you judge your bottle of wine by this unfortunate double-entendre, sediment can also be referred to as ‘wine crystals’ or ‘wine diamonds’. Sounds a bit better than ‘dregs’, right?

Sediment can come in two forms: tartrate and colloids. Tartrates are the larger ‘crystals’ you may find on the end of a cork or clinging to the sides of the bottle or your wine glass. These jagged, burgundy-colored, diamond-like structures are formed when tartaric acid (a natural element in grapes) binds with potassium while exposed to cold conditions. Under these circumstances they form beautiful crystalline salt formations. Colloids, on the other hand, are the smaller and finer-grained sediment which are made of polysaccharides and protein, or can simply be leftover remnants of grape skins, stems or seeds. And yes, both forms of sediment are harmless!

Polysaccharides, for those of us who somehow missed that day of chemistry class…are carbohydrates made up of multiple sugar molecules bonded together. They also contribute to the overall mouthfeel of a wine.

But we’re getting off track.

Although they are usually more prevalent in red wines, they can occur in white wines too! Winemakers will sometimes intentionally leave tartaric sediment in the barrel while the wine ages. This is called ‘sur lie’ aging, which translates to ‘on the lees’ and can supplement and intensify flavor in the finished wine. You may also see this term used in some of the tasting notes for wines you’ve received from any of our six Wine Clubs.

Related: How does an oak barrel influence the aging of wine?

Finally, these crystals, diamonds and gritty-goodness can indicate you have a high quality bottle of wine! The best winemakers know that, oftentimes, less is more when it comes to intervening with methods like filtering. When wines are filtered, it not only takes the sediment out but it also strips the wine of quality features such as mouthfeel and even palate flavor expression. (See our Wine Glossary for further explanations of wine terms!)

So the next time you see wine sediment at the bottom of your glass, rejoice! You could be in for a real treat.