Dry Your Eyes: 'Wine Tears' Finally Explained by Science

Turns out we didn't quite have the full picture of the phenomenon, and a UCLA team has discovered a cause that's literally shocking
Dry Your Eyes: 'Wine Tears' Finally Explained by Science
The research team used a real wailer for its analysis. (Courtesy of Andrea Bertozzi / UCLA)
Mar 30, 2020

Surely you've noticed the slow-dripping streaks encircling the inside of your wineglass after swirling a Port or a hearty Cab: That melancholic vinous phenomenon we call "wine tears" (or "wine legs"). We know a bit about what causes weepy wine—and that the streaks have nothing to do with the wine's quality. But Prof. Andrea Bertozzi of the UCLA department of mathematics realized there was more to it—and it involves little shock waves going through your wine.

Bertozzi told us that the study produced by her and her team, recently published in the journal Physical Review Fluids, was inspired by a lecture on wine tears she had planned previously. “I thought that it would be really good for the students to have a fun lecture. I knew the tears of wine literature,” Bertozzi told Unfiltered. “So I brought in wine and glasses, and some cheese and crackers.” But leading up to the lecture, Bertozzi noticed that previous research hadn’t quite nailed it. “I realized that there was a gap in the literature … they were missing some physics that I thought was actually really important.”

Previous research informed us that wine tears were caused solely by the “Marangoni effect.” For those of us not in the know: As alcohol evaporates from a glass of vino, the surface of the liquid is pushed up the sides of your glass, which is why higher-alcohol wines and spirits have heavier tears. But Bertozzi suspected there was more to it, so, using Port-like wine and a stemless martini glass, the UCLA team got to work.

After glasses were poured and analyzed, the team discovered the specific cause of these weepy patterns: “Reverse undercompressive shocks,” shock waves in which liquids move against the direction of the wave. “It’s caused by a combination of three very simple types of physics,” Bertozzi explained, “One is gravity, the other is the Marangoni stress, and the third thing is the bulk surface tension.” Marangoni draws the wine up, gravity and surface tension pull it down, leaving the sad pattern we all know and love; you see a similar effect on your car’s windshield when driving through rain and wind. Interestingly, it seems that if it weren’t for this effect, the trails in your glass would look more like fingers than tears.

“We sort of discovered [these shocks] 20 years ago,” Bertozzi noted. “But now we have them in wine, which is very, very cool.” More proof that wine and science pair well, and we're a little closer to fully understanding what’s in our glass. Before we've dried those tears along with the rest of it, anyway.


Enjoy Unfiltered? The best of Unfiltered's round-up of drinks in pop culture can now be delivered straight to your inbox every other week! Sign up now to receive the Unfiltered e-mail newsletter, featuring the latest scoop on how wine intersects with film, TV, music, sports, politics and more.

Unfiltered Alcohol Level Extra, Extra

You Might Also Like

Surprising Find Suggests Medieval Scotland Actually Land of Wine-Sipping Big-City Folk

Surprising Find Suggests Medieval Scotland Actually Land of Wine-Sipping Big-City Folk

A recent excavation has found a massive 6th-century settlement in Scotland—by far the …

May 26, 2020
Michelin-Starred Dining for Dummies: The Story Behind the Social-Distancing Mannequins at the Inn at Little Washington

Michelin-Starred Dining for Dummies: The Story Behind the Social-Distancing Mannequins at the Inn at Little Washington

"They're all drinking wine," chef-owner Patrick O'Connell informed us of his famous, albeit …

May 21, 2020
Sarah Jessica Parker Launches New Rosé, Talks Crafting Summer Wine in Parka Weather

Sarah Jessica Parker Launches New Rosé, Talks Crafting Summer Wine in Parka Weather

We caught up with the actor-winemaker today to hear about the many "backs and forths" of …

May 20, 2020
Making the World's First Wine: Who Taught Whom?

Making the World's First Wine: Who Taught Whom?

An archaeologist has published a new book on early Chinese wine techniques that suggests …

May 15, 2020
Man Guzzles Wine from Under Moving Tanker, Elaborate Scam on Champagne Heir: Shocking Acts of Winecrime Everywhere

Man Guzzles Wine from Under Moving Tanker, Elaborate Scam on Champagne Heir: Shocking Acts of Winecrime Everywhere

A highway wine robber in his underwear. A Champenois duped by a fake "secret mission" with …

May 14, 2020
Post Malone Announces Next Summer Hit: His New Rosé

Post Malone Announces Next Summer Hit: His New Rosé

The Grammy-nominated hip-hop star has partnered with a Provence wine hitmaker on his new …

May 13, 2020