Core Viewpoint - Costco is facing a class-action lawsuit for allegedly selling adulterated tequila that contains a significant presence of non-agave sugars, misleading consumers about the quality of its Kirkland Signature tequila products [1][2][3] Group 1: Lawsuit Details - The lawsuit was filed on November 14, 2025, in the U.S. District Court for the Western District of Washington, claiming that Costco's Kirkland Signature tequila is not pure agave as marketed [2] - Affected products include Kirkland Blanco Tequila, Reposado Tequila, Añejo Tequila, Añejo Cristalino Tequila, and Extra Tequila Añejo [2] - The lawsuit alleges that Costco's marketing is deceptive, as consumers are led to believe they are purchasing premium tequila at a premium price [4][5] Group 2: Market Context - Premium tequila sales have increased by 1,270% since 2003, with super-premium brands rising by 1,500% during the same period, indicating a growing consumer demand for high-quality tequila [5] - The definition of tequila is strictly regulated in the U.S. and Mexico, with specific standards for production, labeling, and marketing to prevent adulteration [6][7] Group 3: Scientific Evidence - Scientific testing, including nuclear magnetic resonance (NMR) and isotope testing, has revealed the presence of non-agave sugars in Kirkland tequila products, contradicting Costco's claims of "100% de Agave" [8] - The lawsuit claims that Costco's actions amount to violations of the Racketeer Influenced and Corrupt Organizations (RICO) Act and state consumer protection laws [8][10] Group 4: Regulatory Oversight - The Consejo Regulador Del Tequila A.C. (CRT) is responsible for ensuring compliance with tequila production standards, although it is a private non-profit organization rather than a governmental entity [9][10] - The CRT's board is reportedly dominated by representatives from well-known tequila producers, raising questions about its regulatory effectiveness [10]