Why Is There Sediment in My Wine and Is It OK to Drink?

It’s Friday. You’ve just popped open that bottle of chilled red that the salesperson at the natural wine shop convinced you to buy. As you pour, you find there are bits of sediment floating in your glass. You glance at the bottle. There’s even more sediment along the neck. 

Panic ensues. Did the wine go bad? Is it leftover skins from the grapes? Is it safe to drink?

This might be something you see more and more as natural wine increases in popularity, but sediment in wine isn’t a new thing. Sediment can be a sign of how long the wine has aged, how it was produced, and much more. But is it safe?

Do not fret. It’s not only safe, but in many cases, that sediment in the bottle is intentional. It all comes back to taste and a little bit of chemistry.

Why does wine have sediment?

Bits of sediment in a wine is natural to winemaking. There are a few reasons that sediment will show up in your bottle. The first comes from the grapes themselves.

Grape solids, such as grape skins, seeds, stems, and pulp, are known as pomace. These materials are left over after the initial pressing, known as the “first run,” or “free run,” juice. The winemaker will decide whether to remove the pomace by cold settling. They typically do this immediately with white and some rosé wines, or prior to fermentation for red and orange wines to extract color and tannins.

The cold-settling process chills the wine so the solids settle to the bottom and the juice can be separated. Although rare, it isn’t uncommon to find bits of sediment from these solids in the finished product.

The most common reason for sediment in your wine is leftover yeast. 

Grape juice is fermented into wine with yeast, which transforms the sugars into alcohol. This can happen when yeast is added to the juice, known as inoculated yeast, or with a wild, natural yeast from the air or leftover from the grape skins, known as ambient or indigenous yeast. 

Once the yeast completes fermentation, the dead yeast cells, or “lees,” remain in the barrel or tank. The lees will settle to the bottom over time, which makes it easy to separate for bottling. Again, this process typically happens by chilling the tanks down.

“I will drop as many solids to the bottom of the tank as I can, then I basically decant the wine off of the top of the lees,” says Daniel O’Brien, founder and winemaker at Gail Wines in Sonoma, California. “There is a good chance some could end up in the bottle, but I try to make it clear. I do end up leaving a decent amount of wine behind when it’s time to bottle, but I find that it delivers a better finished wine. I don’t want to put the wine through filters.”

Blair Guthrie, winemaker for Stewart Cellars and Guthrie Family Wines in Napa Valley, says that sediment is common for natural wine produced at a faster rate.

“There shouldn’t be any more sediment in natural wine than [in] a conventional wine that is unfiltered,” says Guthrie. “But I think the main reason we’re getting a lot more sediment in natural wines is because there is a faster turnaround with aging. Most natural wines are not aged for 24 months, like I would age my Cabernet Sauvignon for Stewart. I would say 99% of natural wine is unfiltered, so you’re not removing any of that sediment that’s still in suspension in the wine.”

Sure, a quick turnaround may result in sediment in the bottle. But it could also be a conscious choice to enhance taste.

Sediment in wine can affect the taste, in a good way

The lees can enhance the taste of a wine and give it more texture. Some say the wine becomes creamy and smooth, some say the lees add more of a yeast or brioche-like character, while others say they impart more of a vinegar taste, similar to kombucha.

“Think about aged Champagnes or sparkling wines,” says Guthrie. “When we age them on the lees in the bottle, we’re getting all of that breakdown of the yeast cells, and those wines are quite often bigger in body. They have a yeasty character to them.”

These yeast cells are disgorged before the cork is sealed, but that’s not the case for pét-nat wines, which only go through one fermentation in the bottle. Those dead yeast cells are left, and they add to the characteristics of the wine. 

Some natural winemakers recommend that you turn the bottle over before it’s opened to better distribute the sediment and add more of that complex, textured flavor. Guthrie prefers to settle the yeast and decant the wine to keep its flavors fresh and focused. Essentially, it’s about personal preference. The wine tasting journey is up to you.

It’s also common for wines that age

Ever tap into an older bottle of red and find a healthy amount of sediment at the bottom of your glass or along the neck of your bottle? This is also a natural process for the wine — particularly a red wine that was made well and was meant to age.

“During and prior to fermentation, you are extracting tannins and colors from the grape, which becomes part of the liquid,” says O’Brien. “Over many years, those will end up breaking down. Usually, in some of the greatest wines in the world, especially old Bordeaux and Piedmont reds, you’ll see sediment that settles at the belly of the bottle, depending on how the bottle was stored. Those natural elements that happened way back when the wine was fermented start to separate from the liquid component.” 

This is why a wine that ages will switch from violet and ruby colors to garnet or brick and have a paler intensity.

O’Brien reassures that, from a safety standpoint, a wine with sediment is not a problem to consume, and it can easily be decanted.

Sediment isn’t just found in red wine

Even if a white wine is cold-settled to remove those solids and keep it looking clear and crisp, it’s possible to have sediment. These particles are known as tartrate crystals, or “wine diamonds,” that sit at the bottom of your bottle or glass. 

The crystals can look like little pieces of glass, which is why some wine drinkers are afraid of them, but they are safe to consume. And they can be decanted just as easily as other sediment.

Wine diamonds happen because the tartaric acid in the wine reacts with potassium in cold temperatures. Winemakers will avoid this by cold stabilizing the wine, meaning they will chill it down and add bentonite to the tank to remove the solids that create these crystals in the first place. This is a cosmetic process to make sure the white wine looks clear, but winemakers like O’Brien steer clear of the process.

“If you do see that crystallization, that’s a good sign,” says O’Brien. “That means the wine was made properly.”

Whether it’s an aged white wine sprinkled with diamonds, an old Bordeaux you share with loved ones, or a chilled red from the natural wine shop around the corner, it’s safe to say that sediment can be a very good thing in wine, and nothing to worry about. So drink up and carry on.