Is your favorite tequila a sham? A recent class-action lawsuit is accusing Costco of misleading consumers about the quality of its popular Kirkland Signature tequila. This case, filed by the consumer-rights law firm Hagens Berman, alleges that the retailer knowingly sells adulterated tequila, containing non-agave sugars, despite marketing it as a premium, 100% agave product.
This lawsuit, filed on November 14, 2025, in the U.S. District Court for the Western District of Washington, targets Costco's Kirkland Signature Blanco, Reposado, Añejo, Añejo Cristalino, and Extra Añejo tequilas. The core of the complaint is that these tequilas, despite being labeled as '100% DE AGAVE' and '100% AGAVE AZUL,' have been found through scientific testing to contain non-agave sugars.
"We believe Costco’s marketing of its tequila products is two-faced," stated Steve Berman, highlighting the alleged discrepancy between the product's premium price and its actual composition.
But here's where it gets controversial... The lawsuit points out that consumers pay a premium for tequila made from 100% Blue Weber agave, a crop known for its long growing season and difficult harvesting. The suit also mentions that sales of premium tequila have surged, growing by 1,270% since 2003, with super-premium brands seeing a 1,500% increase over the same period.
The definition of tequila is strictly regulated in the U.S. and Mexico. The Tequila NOM (the official Mexican standard) sets strict standards for production, labeling, and marketing to prevent adulteration. To be labeled as "100% agave," a tequila's fermentation should only use sugars from the tequilana weber blue variety Agave.
The lawsuit claims that scientific testing, including nuclear magnetic resonance (NMR) and isotope testing, reveals the presence of non-agave sugars in Kirkland Tequila Products, contradicting Costco's labeling.
And this is the part most people miss... The lawsuit also brings claims of violation of state consumer protection laws pertaining to unfair competition, unfair trade practices, and fraudulent concealment. The law firm has also filed a class-action lawsuit against Diageo, the maker of Casamigos and Don Julio tequila brands, over similar allegations.
A Tequila Cartel? The lawsuit also delves into the regulatory body, Consejo Regulador Del Tequila A.C. (CRT), which is responsible for ensuring compliance with the Tequila NOM. The suit claims that although the CRT presents itself as a regulatory body, it's a private non-profit organization composed of members from across the Agave-Tequila production chain, with its board of directors and committees dominated by representatives of well-known tequila producers.
Attorneys representing consumers seek to stop Costco's allegedly deceptive practices and recover losses for those who purchased the affected Kirkland Signature tequila.
What do you think about these allegations? Do you believe that the tequila industry is adequately regulated? Share your thoughts in the comments below!
