In the world of premium tequila, authenticity is everything. But recent lawsuits have shaken two of the biggest names in the industry—Casamigos and Don Julio—with claims that what’s in the bottle might not match what’s on the label.
In May 2025, multiple class action lawsuits were filed in U.S. courts accusing Diageo, the global beverage giant behind both brands, of false advertising and deceptive marketing. At the center of the controversy is the iconic phrase “100% agave.” It’s a designation that tequila lovers trust. It means no added sugar, no cheap filler alcohol—just pure Blue Weber agave spirit. But the lawsuits say otherwise.
According to the complaints, independent laboratory tests show that Casamigos Blanco and Don Julio Blanco might contain less than 50% agave-derived alcohol, with the rest allegedly made from cane or other non-agave sources. That would make them mixtos, not “100% agave” tequilas—and a major breach of consumer trust. The lawsuits seek over $5 million in damages and demand that Diageo stop marketing the products with those claims.
Diageo Fights Back
Diageo, which acquired Casamigos in 2017 for nearly $1 billion, isn’t taking the allegations lightly. The company calls them “outrageous,” “baseless,” and “categorically false.” In statements to the press, Diageo insists that all of their tequilas are made with 100% Blue Weber agave, fully compliant with both Mexican regulations (via the Tequila Regulatory Council, CRT) and U.S. labeling laws. They’ve vowed to vigorously defend their brands in court.
So who’s telling the truth?
That may depend on how you define “truth.” The lawsuits reference carbon isotope ratio testing—a method that can detect whether alcohol in a sample comes from agave or other sources like sugarcane. Plaintiffs claim the results show significant cane-derived content. Diageo, meanwhile, suggests such testing is unreliable or misinterpreted.
A Bigger Problem: Transparency in Tequila
The lawsuits don’t stop at just Casamigos and Don Julio. They hint at a larger, systemic issue—accusing not only Diageo, but also the CRT of failing to enforce real standards and enabling a long-standing culture of misleading labels.
In fact, the CRT has banned the use of the phrase “additive-free” on bottles, arguing that it’s not officially recognized in Mexican regulations. This move has caused serious backlash from transparency advocates, especially the team behind Tequila Matchmaker’s Additive-Free program, which independently verifies brands that don’t use flavor or color additives.
Earlier this year, the CRT even sued the creators of Tequila Matchmaker in U.S. court, alleging trademark violations—after already raiding their lab in Mexico. Many see this as an attempt to silence a group that’s been pushing for more honesty in the industry.
What’s at Stake
For tequila fans, this isn’t just a legal squabble—it’s about trust. People spend premium prices for Casamigos, Don Julio, and other high-end bottles believing they’re drinking something pure, crafted, and traditional. If the lawsuits are proven right, it could cause a massive shake-up in how tequila is marketed and regulated.
For now, the courts will decide whether Diageo misled millions of consumers. But win or lose, this controversy has already started a bigger conversation: What does “100% agave” really mean? And who gets to decide? One thing’s for sure—this battle is far from over. And the future of premium tequila may depend on its outcome.
