MIAMI — Ariel Glazer, a resident of Florida, has initiated a class-action lawsuit against Costco, asserting that the Kirkland Signature tequila line is falsely branded as “100% agave.” The legal action, filed on October 31 in a Miami federal court, claims that specialized testing shows the tequila contains alcohol not sourced from blue agave plants, which is the only ingredient permitted for authentic tequila under Mexican law.

The lawsuit targets five specific Kirkland tequila variants: Blanco, Reposado, Añejo, Añejo Cristalino, and Extra Añejo. These bottles prominently display labels stating “100% DE AGAVE” and “100% AGAVE AZUL” and are sold across Costco stores and online, priced between $18.69 and $48.99 each.

The complaint highlights that tests on Kirkland Signature Añejo Cristalino revealed alcohol content derived from sources other than agave plants, suggesting ingredients more akin to sugarcane or corn alcohol. The lawsuit contends these findings are inconsistent with the standards for 100% agave tequila, and even fall short of the criteria for “mixto” tequilas, which under Mexican law can include up to 49% non-agave sugars.

Given that all Kirkland tequilas originate from a common base of Blanco tequila distillation, the lawsuit argues that this alleged contamination impacts the entire product line.

Because all Kirkland tequilas start from the same base distillation of Blanco tequila, the lawsuit argues the contamination affects the entire product line.

True tequila must be made exclusively from Blue Weber agave plants grown in specific regions of Mexico, primarily Jalisco state. The plants take five to 10 years to mature before harvest, making authentic agave spirits significantly more expensive than alternatives.

The lawsuit notes that even adding small amounts of cheaper alcohols like sugarcane-derived ethanol would violate both Mexican standards and U.S. labeling requirements under the Federal Alcohol Administration Act.

The plaintiff, who purchased a bottle of Kirkland Reposado from a Costco in Royal Palm Beach, Florida, on Oct. 28, is seeking to represent a nationwide class of consumers who bought the products.

The lawsuit includes claims for negligence, negligent misrepresentation, unjust enrichment and violations of consumer protection laws.

“If Plaintiff and others similarly situated had known the truth of the ingredients in the Products, they would not have purchased the Products or would have paid less for them,” the complaint states.

Costco has not yet responded to the allegations in court.