A Seattle judge dismisses a class action over Costco's "100% agave" Kirkland tequila labels

A federal judge in Seattle has dismissed a proposed class action against Costco that accused the retailer of misleading shoppers by labeling several Kirkland Signature tequilas as “100% de agave” and “100% agave azul.”

The case was filed in the U.S. District Court for the Western District of Washington in Seattle by the consumer rights firm Hagens Berman on behalf of 14 plaintiffs. The lawsuit, filed in November 2025, alleged that Costco knowingly sold tequila containing a significant amount of non-agave sugars while marketing the products as entirely agave-based.

The challenged products included Kirkland Blanco Tequila, Reposado Tequila, Añejo Tequila, Añejo Cristalino Tequila and Extra Añejo Tequila. According to the complaint, consumers paid premium prices for those bottles because they believed the tequila was made only from blue agave. The suit said buyers either would not have purchased the products or would have paid less if they had known the contents allegedly did not match the labeling. The bottles at issue were sold in a price range of about $18.69 to $48.99.

To support the claims, the plaintiffs relied on results from Site-Specific Natural Isotope Fractionation-Nuclear Magnetic Resonance, or SNIF-NMR, testing. That method is used in food and beverage compliance work by some government and regulatory bodies to examine product composition and authenticity. The plaintiffs said the testing showed the presence of sugars from sources other than agave.

The lawsuit also alleged that Costco obtained a false “100% de agave” certification that allowed the company to market and sell the tequila in the United States at higher prices. Costco denied the allegations and defended the labeling by pointing to product testing conducted in Mexico that, according to the company, produced different results from the plaintiffs’ SNIF-NMR analysis.

Costco also argued that similar lawsuits had already shown limits in using SNIF-NMR results alone to overturn “100% agave” labeling claims in U.S. court. The dismissal in Seattle adds to a growing list of disputes over how such claims should be tested and proved when tequila is sold to American consumers under premium quality statements.

The ruling follows another recent court defeat for plaintiffs making similar claims against major tequila brands. Last month, a judge in New York dismissed a case against Diageo involving Casamigos and Don Julio after finding the testing offered in that matter was insufficient. A separate class action against 818 Tequila over “100% agave” labeling remains active, and the company has sought several times to have that case dismissed.

The Costco case matters beyond one retailer because it touches a larger issue in the U.S. spirits market: how courts evaluate scientific testing in disputes over authenticity and labeling. For tequila producers, importers, distributors and retailers, the outcome could shape how aggressively companies defend “100% agave” claims and how difficult it may be for consumers or competitors to challenge those statements in court. It may also affect how compliance documentation and laboratory evidence are used in future litigation involving tequila and other premium beverage categories.

Neither the name of the judge nor additional details of the dismissal order were provided in the source report. The decision nonetheless marks a significant win for Costco in a case that targeted one of the most important quality claims used in tequila marketing in the United States.