Diageo Just Beat the “100% Agave” Lawsuit Against Don Julio and Casamigos

Diageo Just Beat the “100% Agave” Lawsuit Against Don Julio and Casamigos

A federal judge in Brooklyn has dismissed the lead class action accusing Diageo of mislabeling its two biggest tequilas. It is a major win for Diageo. It is not a ruling that the tequila was proven pure, and it is not a ruling that the lab testing was fake. The case fell on a much simpler problem: five samples.

By Vim, Editor of 12×75

In brief

• On October 1, 2026, US District Judge LaShann DeArcy Hall dismissed Pusateri v. Diageo North America (E.D.N.Y., 1:25-cv-02482), the lead proposed class action over “100% agave” labeling on Casamigos and Don Julio.
• The complaint relied on lab testing of five samples. The judge questioned how that could support an inference of what Reuters reported as “ubiquitous, systemic mislabeling.”
• The court also found the plaintiffs had not shown that the named buyers themselves purchased affected bottles.
• This was a dismissal at the pleading stage, not a trial verdict. The judge did not find every bottle is 100% agave, and did not rule carbon-isotope testing invalid.
• Diageo said it was gratified. Plaintiffs’ lawyer Steve Berman said the ruling gets the record wrong and signaled they may seek reconsideration. Related cases had been paused pending this one.

What the judge decided

The plaintiffs alleged they paid premium prices for tequila marketed as “100% agave,” “100% Blue Weber Agave” or “Tequila 100% Agave Azul,” and relied on independent laboratory testing which, they said, suggested some samples contained alcohol from non-agave sources. Their theory was simple: had the labels been accurate, they would have paid less or bought something else.

The judge’s problem was with the gap between that evidence and that theory. According to Reuters, she questioned how a study of only five samples could support an inference of systemic mislabeling across two enormous brands. The court found the plaintiffs had not plausibly shown widespread adulteration, had not shown the named buyers bought affected bottles, and had not established a sufficiently direct injury.

Why five samples were not enough

This is the heart of it, and it is worth separating the science from the law, because they ask different questions.

Casamigos and Don Julio sell millions of bottles a year. Even if a handful of samples were genuinely anomalous, that alone does not tell you whether the issue is a one-off, a single batch, a testing artifact, a counterfeit, or a systemic production practice. Those are wildly different explanations with wildly different legal consequences, and the complaint did not give the judge enough to choose between them.

What the ruling does not mean

Three things this decision is not, because all three will be claimed somewhere.

It is not a finding that the tequila is 100% agave

This was a dismissal at the pleading stage. The court asked whether the plaintiffs had alleged enough facts to proceed, not whether the product is pure. No trial took place and no evidence was weighed.

It is not a ruling that isotope testing is invalid

Carbon-isotope analysis, the method behind these cases, is an established tool for identifying the botanical source of alcohol. The judge did not rule it unreliable. She ruled that this particular testing, on this particular number of samples, did not plausibly support these particular claims.

It is not necessarily the end

Plaintiffs’ lawyer Steve Berman of Hagens Berman said the ruling “gets the record wrong” and indicated they may ask the court to reconsider. Further litigation is possible.

Diageo’s position

Diageo has rejected the allegations throughout, calling them baseless as the case proceeded in 2025 and maintaining that bottled Casamigos and Don Julio labeled 100% agave are exactly that. After the ruling, Reuters quoted the company as saying it was gratified the court had rejected the adulteration allegations.

It is a significant win, and Diageo is entitled to it. A company accused of mislabeling its two flagship tequilas has seen the lead case dismissed, and the burden now sits firmly with anyone who wants to bring a similar claim: they will need far more than a handful of samples.

What happens to the other cases

This was the lead case, and several related federal actions had been paused while it was decided. That is why the ruling matters beyond one lawsuit: the obvious question now is whether the same reasoning, particularly the absence of broad, product-wide evidence, weakens those related claims too.

It is worth being careful about the wider docket. The cases against Lunazul, Teremana and others are separate suits against different companies, built on their own testing. This ruling does not decide them. But any judge hearing a similar complaint will now have a well-publicised precedent to consider, and plaintiffs everywhere will be thinking hard about sample size.

The practical consequence is probably a higher bar rather than an end to the litigation. Expect future complaints, if they come, to arrive with much larger testing programmes and stronger links between the tested bottles and the named buyers.

Why “100% agave” is worth fighting over

“100% agave” is a regulated category, not a marketing flourish. Under Mexico’s tequila standard it means all the fermentable sugars came from blue Weber agave, as opposed to mixto tequila, which may legally use up to 49% sugars from other sources. It is the line between premium and standard tequila, and it is the claim the entire top end of the category is built on.

That is precisely why the lawsuits happened, and why their failure here does not end the underlying conversation. Consumers have spent years learning to look for those words, to check which bottles are independently verified, and to ask about production. It is also why Mexico is deepening laboratory cooperation with US regulators: authenticity is now a trade issue as well as a consumer one.

What it means if you buy tequila

Practically, nothing changes on the shelf. Casamigos and Don Julio were legally sold as 100% agave before the ruling and they are now. If you like them, nothing in this decision gives you a reason to stop, and nothing in the original suit ever proved one.

What the case leaves behind is a market that pays more attention. The transparency questions consumers have been asking, about additives, diffusers, sweeteners and which distillery made the bottle, did not depend on this lawsuit and will not disappear with it. If those things matter to you, the reliable route remains the same one it was before: buy from producers that publish their production and submit to independent verification. My best tequila guide and the Don Julio hub cover the bottles in detail.

Quick answers

Did Diageo win the Don Julio and Casamigos lawsuit?

Yes. On October 1, 2026, a federal judge dismissed the lead proposed class action alleging Diageo falsely labeled Casamigos and Don Julio as 100% agave.

Does the ruling prove Don Julio and Casamigos are 100% agave?

No. It was a dismissal at the pleading stage. The judge found the plaintiffs had not alleged enough to proceed; she did not make a finding about the composition of the tequila.

Why was the 100% agave lawsuit dismissed?

The complaint relied on testing of five samples, which the judge found could not plausibly support claims of systemic, brand-wide mislabeling. The plaintiffs also had not shown the named buyers purchased affected bottles.

Is the case over?

Not necessarily. Plaintiffs’ lawyers said the ruling gets the record wrong and may seek reconsideration. Related cases had been paused pending this decision.

Did the judge say isotope testing is unreliable?

No. The ruling concerned whether this testing, on five samples, supported these claims, not the validity of the method itself.

The last word

Diageo has won the round that mattered most, and it deserves to have that reported accurately. So does the rest of the story. The court did not vindicate the tequila and did not discredit the science. It said that five samples cannot stand in for two brands, which is a sensible legal principle and a long way from a certificate of purity.

Sources

• Reuters: Diageo defeats false-labeling lawsuit over 100% agave tequilas, October 1, 2026
• Law360: Diageo beats tequila purity suit due to sparse testing
• Reuters: lawsuit accuses Diageo of duping US consumers about tequila purity, May 2025
• Reuters: Diageo calls tequila purity allegation baseless, July 2025
• Hagens Berman: Casamigos and Don Julio case page

This article describes a court ruling on a motion to dismiss. The plaintiffs’ laboratory claims were allegations, and Diageo denied them; no court has found either brand mislabeled. Further proceedings, including reconsideration, remain possible. Correct as of October 2, 2026. Please drink responsibly.