A New York judge found the tests questioning the “100% agave” label on Casamigos and Don Julio insufficient
Diageo, owner of Johnnie Walker, has won the first round of the loudest legal fight in the tequila world. On October 1, federal judge LaShann DeArcy Hall, of the Brooklyn court in New York, dismissed the class action accusing the company of selling Casamigos and Don Julio tequilas as “100% agave,” according to Mezcalistas and The Daily Pour.
The suit was filed in 2025 by buyers of the two brands. They claimed the bottles contained alcohol that did not come from blue agave and that they had therefore paid a high price for a product different from the one advertised. The accusation rested on a laboratory test using nuclear magnetic resonance, which measures the ratio of carbon isotopes in the fermented alcohol to indicate which plant it came from, The Daily Pour reported.
For the judge, the evidence did not support the accusation. The study submitted analyzed only five samples, a number she considered too small to conclude that there was broad, systematic mislabeling. The ruling also noted that the plaintiffs did not link the bottles they bought, in time or place, to the bottles tested, and therefore did not show how they were harmed.
Diageo welcomed the decision and reaffirmed that Casamigos and Don Julio are made from 100% blue Weber agave. When it moved to dismiss, the company had already argued that the test used by the plaintiffs lacked scientific validation. On the other side, Steve Berman, partner at the law firm Hagens Berman, which represents the buyers, said the ruling misreads the case. He told Mezcalistas he will ask the judge to reconsider and is ready to take the case to an appeals court.
Under Mexican rules, only tequila made solely from blue agave sugars may carry “100% agave” on the label; others may use some sugar from another source. That phrase is what justifies the higher price of top bottles. According to The Daily Pour, similar suits, using the same kind of test, remain open against Teremana, 818, Lunazul, Cincoro and Kirkland Signature, which keeps the issue alive in US courts.
The outcome changes nothing, for now, for people buying tequila in Brazil, but the industry is watching closely: a win for consumers would open the door to challenging labels with the same lab method.
Sources: Mezcalistas (October 1, 2026), The Daily Pour (October 1, 2026).
