Costco Faces Class-Action Lawsuit Over Kirkland Signature Tequila

Costco Wholesale Corp is under scrutiny as a class-action lawsuit was filed against the retail giant on November 14, 2025, by Seattle-based consumer rights law firm Hagens Berman. The lawsuit alleges that Costco knowingly marketed its Kirkland Signature tequila products as "100% DE AGAVE" and "100% AGAVE AZUL," despite claims that scientific testing has revealed these products contain a significant presence of non-agave sugars, thus rendering them adulterated.

Steve Berman, managing partner and co-founder of Hagens Berman, expressed strong sentiments about the retailer's marketing practices. "We believe Costco’s marketing of its tequila products is two-faced, and that despite marketing it as a premium – and reflecting that in its price – consumers have been misled about the quality of Kirkland Signature,” he stated. Berman emphasized that consumers who purchased Kirkland tequila did not receive the premium product for which they paid.

The lawsuit was filed in the U.S. District Court for the Western District of Washington and targets several Kirkland tequila products, including:

Consumers who have purchased these products may be affected by the allegations and are encouraged to understand their rights.

The lawsuit highlights the explosive growth of the premium tequila market, noting that sales of premium tequila have surged by an astonishing 1,270% since 2003, with super-premium brands experiencing a 1,500% increase over the same period. This growth can be attributed to a rising consumer demand for authentic, high-quality tequila, which has led retailers like Costco to capitalize on the trend.

According to the lawsuit, the production and labeling of tequila are strictly regulated in both the U.S. and Mexico. The Tequila NOM imposes stringent requirements to prevent adulteration, emphasizing that fermentation must not be enhanced with sugars not derived from the blue agave plant.

The lawsuit cites scientific testing methodologies, including nuclear magnetic resonance (NMR) and isotope testing, which reportedly demonstrate the presence of non-agave sugars in Kirkland tequila products. These findings contradict Costco's claims of "100% de Agave" and "100% Blue Agave," raising questions about the integrity of the products being sold under the Kirkland brand.

Furthermore, the lawsuit points to regulatory concerns regarding the Consejo Regulador Del Tequila A.C. (CRT), a private non-profit organization that oversees compliance with the Tequila NOM. The CRT is criticized for being composed of members from the Agave-Tequila production chain, including representatives of major tequila producers, potentially creating conflicts of interest in its regulatory role.

The lawsuit not only seeks to address the alleged deceptive marketing practices but also cites violations of the Racketeer Influenced and Corrupt Organizations (RICO) Act. This law is typically associated with organized criminal behavior, and the lawsuit additionally claims violations of state consumer protection laws related to unfair competition, unfair trade practices, and fraudulent concealment.

Attorneys representing the consumers aim to halt Costco's purported deceptive practices and recover losses incurred by consumers who purchased the affected Kirkland tequila products.

As the case unfolds, it sheds light on the broader implications of consumer rights in the premium beverage market. With Costco's reputation at stake, the outcome of this lawsuit may set a significant precedent for how retailers market tequila and other alcoholic beverages in the future.