Don Julio and Casamigos Tequila Emerge Victorious in ‘100% Agave’ False Labeling Lawsuit

(Photo: AP Photo/Jenny Kane)

British spirits giant Diageo has persuaded a judge to dismiss a lawsuit that accused its flagship tequila brands Don Julio and Casamigos of false advertising. The lawsuit was one of nearly a dozen filed against prominent tequila distillers over the past year and a half, and its outcome may set the precedent for future rulings against the likes of Dwayne “The Rock” Johnson’s Teremana and Kendall Jenner’s 818.

On Wednesday, US District Judge LaShann DeArcy Hall said that the plaintiffs failed to prove the systemic or widespread adulteration of Diageo’s tequilas. The lawsuit, first filed in May 2025 by a group of individual buyers and restaurants, claimed that Don Julio and Casamigos contained a significant amount of non-agave alcohol despite being labeled as “100% agave.”

Plaintiffs claimed that they paid a premium price for a deceptively marketed tequila — a claim that, if proven true, could qualify as personal injury in court.

Judge DeArcy Hall was unconvinced. In a memorandum to dismiss the case, the court said that the plaintiffs did not provide enough evidence from their alleged laboratory testing. The court also took issue with the study’s small sample size. Plaintiffs only submitted evidence from five samples of tequila, which the court claimed was too small to “reasonably infer that a defendant was engaging in ubiquitous, systemic mislabeling.”

Steve Berman, a lawyer for the plaintiffs, told Reuters that the ruling “gets the record wrong” and added that they may ask the court to reconsider its decision.

Representatives for Diageo — which has long denied the accusations and at one point likened the lawsuit to flat-eartherism — applauded the development.

“We are gratified that the court rejected plaintiffs’ adulteration allegations in their entirety,” a Diageo spokesperson told The Daily Pour in an email statement. “Casamigos and Don Julio are made from 100% Blue Weber agave. We’re proud of our tequilas, confident in their quality and integrity, and pleased to put these baseless claims behind us.”

Plaintiffs’ claims were based on a lab testing technique called nuclear magnetic resonance, which can purportedly isolate a carbon “fingerprint” in alcohol that corresponds to the plant source of sugars used during fermentation. Based on these testing methods, the lawsuit claimed that tequilas like Casamigos Blanco contained as little as 33% agave-derived ethanol in each bottle.

The court didn’t spend much time dwelling on the validity of the technique. Instead, Judge DeArcy Hall argued that the plaintiffs failed to connect the dots between the tests and Diageo’s tequilas writ large.

According to the dismissal, plaintiffs only submitted the laboratory testing’s methodology, the results of the testing and the year that the testing was commissioned. Plaintiffs did not establish a “temporal or geographic” link between their purchased products and the laboratory testing, undermining claims that they had been “personally injured” by deceptively labeled liquor.

Since the test’s sample size was too small to extrapolate its findings onto all Casamigos and Don Julio products, the plaintiffs failed to prove “that adulterations were so widespread that the bottles they purchased were likely adulterated.”

Diageo is widely considered to be the largest spirits conglomerate in the world. In addition to Casamigos and Don Julio, the British company is responsible for Guinness, Johnnie Walker, Crown Royal, Smirnoff and Aviation American Gin, among others.

The Diageo case was the first of several suits filed against prominent tequila distillers since March 2025. Similar cases against Lunazul, Cincoro, Teremana, 818 and Costco’s Kirkland Signature are still ongoing in courts across the country. Each lawsuit has accused a brand of adulterating its tequila with non-agave-derived alcohol, and all have based their claims on nuclear magnetic resonance testing or similar methods of carbon isotope ratio analysis.