How are wines filtered?

Ask Dr Vinny

Hello there! I'm Dr. Vinifera, but you can call me Vinny. Ask me your toughest wine questions, from the fine points of etiquette to the science of winemaking. And don't worry, I'm no wine snob—you can also ask me those "dumb questions" you're too embarrased to ask your wine geek friends! I hope you find my answers educational, empowering and even amusing. And don't forget to check out my most asked questions and my full archives for all my Q&A classics.

Dear Dr. Vinny,

How are wines filtered?

—Jeri Sue H., Deming, N.M.

Dear Jeri Sue,

There are four different methods winemakers use to clarify a wine. That means removing sediment—dead yeast cells and bits of grapes. This is done not only for cosmetic reasons (vintners generally prefer clear wine to murky wine), but also to protect against a wine re-fermenting in the bottle. Other winemakers like to leave all that stuff in there, feeling it adds to the texture and flavor of a wine.

The first method is racking, and it’s the most unobtrusive way. You move wine from one barrel to another, but as you do so, you leave the last bit of wine in the first barrel where all the sediment has settled.

You can also filter the wine, using various filter pads or membranes, which trap the sediment. There’s also a process called fining, where you add something that binds to the sediment—typically a type of protein, such as egg whites. The fining agents coagulate with the sediment, making them bigger and therefore easier to trap in a filter, or to leave at the bottom of a barrel if you rack again. (The fining agent is not meant to remain present in the finished, bottled wine.)

The last method is cold stabilization, and that’s meant to avoid those crunchy bits of tartaric acid that look like rock candy or shards of glass. They’re harmless, but can be annoying. The wine is chilled severely, and then the crystals are removed so you don’t have to deal with them.

—Dr. Vinny

Winemaking Techniques Explained Ask Dr. Vinny

More In Dr. Vinny

How do you clean wineglasses to a spot-free, clear shine?

Wine Spectator's expert Dr. Vinny offers tips for cleaning fine stemware.

May 22, 2019

What does the word “unctuous” mean in a wine tasting note?

Wine Spectator's expert Dr. Vinny explains the term "unctuous," typically ascribed to …

May 20, 2019

Are collectible wines still collectible after the wine has gone bad?

Wine Spectator's expert Dr. Vinny talks to Penfolds winemaker Peter Gago about 50-year-old …

May 17, 2019

Why aren't bottles stored on their sides at wine stores?

Wine's Spectator's expert Dr. Vinny explains why wine bottles need to be stored on their …

May 15, 2019

Is there a polite way to tell a winemaker that I'm not enjoying their wines?

Wine Spectator's expert Dr. Vinny suggests a few etiquette tips for kindly declining an …

May 13, 2019

Do you swirl a glass of sparkling wine?

Wine Spectator's expert Dr. Vinny explains why there's no need to swirl a glass of …

May 10, 2019
WineRatings+

WineRatings+

Xvalues

Xvalues

Restaurant Search

Restaurant Search