The Costco tequila lawsuit is a proposed class action claiming that Kirkland Signature tequila, sold under a “100% Agave” label, is actually cut with cheaper alcohol derived from sources like cane sugar. The active case is pending in the U.S. District Court for the Western District of Washington, and Costco has moved to dismiss it.
What the Lawsuit Claims
The complaint, Salisbury v. Costco Wholesale Corporation (Case No. 2:25-cv-02277), was filed on November 14, 2025, and is being handled by the firm Hagens Berman.1Hagens Berman Sobol Shapiro LLP. Costco Kirkland Signature Adulterated Tequila Class Action It targets five Kirkland Signature tequila products: Blanco, Reposado, Añejo, Añejo Cristalino, and Extra Añejo.2Hagens Berman Sobol Shapiro LLP. Consumers Sue Costco Alleging Kirkland Signature Tequila Is a Sham Each bottle carries labeling declaring the product “100% DE AGAVE” or “100% AGAVE AZUL.” Plaintiffs say those declarations are false.
The core evidence in the complaint comes from laboratory testing of Kirkland Signature Añejo Cristalino. Plaintiffs say they used Nuclear Magnetic Resonance testing and carbon isotope ratio analysis, and that the results showed levels of cane sugar so high the product would not even qualify as a “mixto” tequila, the lower tier that requires only 51% agave-derived alcohol.3Delish. Costco Kirkland Tequila Lawsuit4The Spirits Business. Costco Faces Lawsuit Over 100% Agave Claim Because plaintiffs contend all five Kirkland tequilas share the same base spirit, they argue the Cristalino results implicate the entire line.
Reporting on the complaint has cited more specific numbers. Kirkland Blanco allegedly tested at only 60% to 80% agave-derived ethanol, and Kirkland Reposado at just 5% to 25%.5KOIN. Costco Kirkland Brand Tequila Class Action Lawsuit If accurate, both figures would fall below the 51% floor for standard tequila, let alone the 100% required by the label.
An earlier suit filed in Florida, Glazer v. Costco Wholesale Corporation, raised similar allegations but was voluntarily dismissed by the plaintiff on January 29, 2026, and formally closed the following week.6PACER Monitor. Glazer v. Costco Wholesale Corporation The Washington case is now the live one.
The Legal Claims Being Brought
The Washington complaint goes further than typical false-advertising claims. Plaintiffs allege that Costco violated the federal Racketeer Influenced and Corrupt Organizations Act, arguing the company knowingly profited from a scheme to substitute cheaper alcohol for agave while charging a premium price.5KOIN. Costco Kirkland Brand Tequila Class Action Lawsuit The complaint also brings state-level claims for unfair competition, unfair trade practices, and fraudulent concealment.2Hagens Berman Sobol Shapiro LLP. Consumers Sue Costco Alleging Kirkland Signature Tequila Is a Sham
Neither complaint puts an exact figure on the price premium consumers allegedly paid because of the labeling. The now-closed Florida version stated that the products sell for between $18.69 and $48.99 per bottle and that the aggregate amount in controversy for the proposed nationwide class exceeds $5 million.7ClassAction.org. Glazer v. Costco Wholesale Corporation Complaint Plaintiffs seek unspecified damages, restitution, and an injunction to stop Costco from marketing the products as 100% agave.
Who Actually Makes Kirkland Tequila
Costco does not distill the product. Kirkland Signature tequila is a contract brand, made in Mexico and labeled for Costco. All current varieties carry NOM 1173, which corresponds to Corporativo Destileria Santa Lucia, a distillery in Tesistán near Guadalajara in Jalisco.8VinePair. Major Distilleries That Make Costco Kirkland Liquor9Tasting Table. This Is Who Really Makes Kirkland Tequila Santa Lucia also produces for other brands, including El Destilador and La Puerta Negra.4The Spirits Business. Costco Faces Lawsuit Over 100% Agave Claim
That arrangement is part of the legal fight. One industry analysis noted that it remains “extremely challenging to prove that Costco was actually in on the game,” because contract brands typically rely on Mexico’s Tequila Regulatory Council certification rather than doing their own testing.10Mezcalistas. Costco Implicated in Adulterated Tequila Scandal The lawsuit names only Costco. It does not name the distillery or any supplier in Mexico.
The Regulatory Backdrop
Under Mexican law, tequila production is governed by the official standard NOM-006-SCFI-2012. Products labeled “100% Agave” must be made exclusively from Blue Weber agave sugars and bottled within the Denomination of Origin, which covers parts of Jalisco, Nayarit, Michoacán, Guanajuato, and Tamaulipas. Standard tequila requires only 51% agave-derived sugars. The Tequila Regulatory Council, known as the CRT, is the sole body authorized to inspect and certify compliance.11Consejo Regulador del Tequila. Our Tequila
Plaintiffs attack the CRT’s independence. Their complaint alleges the CRT is “not a governmental entity” but a private nonprofit whose board is dominated by the tequila producers it regulates.2Hagens Berman Sobol Shapiro LLP. Consumers Sue Costco Alleging Kirkland Signature Tequila Is a Sham In early 2025, Mexican agave growers reportedly staged protests alleging that major tequila companies were using non-agave ingredients and that the CRT was failing to enforce its own standards.5KOIN. Costco Kirkland Brand Tequila Class Action Lawsuit
There is a caveat worth understanding. Mexican rules permit up to 1% of certain post-distillation additives, such as sweeteners, colorants, or glycerin, in tequila without label disclosure. Critics of this wave of lawsuits have argued those permitted additives, which can be derived from cane sugar or corn, could skew isotope testing and make it look as though non-agave ethanol is in the base spirit when it may only be trace additives.12KQED. What’s in Your Tequila? California Lawsuit Claims Some Labels Mislead Consumers The full lab methodology behind the plaintiffs’ testing has not been publicly released, so independent verification is not possible at this stage.
Costco’s Response and Where the Case Stands
Costco has not addressed the adulteration allegations in a public statement. Its response has been procedural. On April 21, 2026, Costco filed a motion to dismiss the Washington case, arguing that a U.S. court lacks authority to decide it because determining what qualifies as “100% agave tequila” falls under Mexico’s exclusive sovereign authority.13Law360. Costco Says 100% Agave Tequila Suit Belongs in Mexico Plaintiffs’ opposition was due June 2, 2026. Plaintiffs filed an amended complaint on March 9, 2026, and the case is before Judge Kymberly K. Evanson.1Hagens Berman Sobol Shapiro LLP. Costco Kirkland Signature Adulterated Tequila Class Action
The case has not reached class certification. No settlement has been proposed. Whether it advances to discovery, which would potentially force Costco and its suppliers to produce production records and internal testing data, depends on how the court rules on the motion to dismiss. Consumers who bought Kirkland Signature tequila and want to follow the case or contact plaintiffs’ counsel can reach Hagens Berman at 1-888-381-2889.1Hagens Berman Sobol Shapiro LLP. Costco Kirkland Signature Adulterated Tequila Class Action
Part of a Wider Wave
The Costco case is not isolated. Diageo, the parent of Don Julio and Casamigos, faces class actions in New York, Florida, and California making the same type of adulteration claims, with the lead case pending in the Eastern District of New York. Diageo has called the claims “outrageous and categorically false.”14Hagens Berman Sobol Shapiro LLP. Casamigos Don Julio Tequila Separate suits have targeted 818 Tequila and Cincoro Tequila on similar grounds.15The Spirits Business. 818 Tequila Challenges 100% Agave Lawsuit None of those cases have been consolidated with the Costco litigation, and each will rise or fall on its own record.