Tequila must be made with at least what percentage of Blue agave?

Tequila must be made with at least 51% blue agave to legally be labeled as tequila. This means that a spirit made with this minimum percentage can include other sugars but must predominantly utilize blue agave as its source of fermentable sugars. The percentage reflects the legal standards set by the Mexican government for production of tequila, which is a protected designation.

Spirits that contain 100% blue agave are often labeled as "100% agave" or “100% puro de agave,” denoting that nothing else has been added. However, the minimum to qualify as tequila remains at 51%. Therefore, the option indicating 51% is the correct choice for this question, as it aligns with the regulatory definitions governing the production of tequila.