Here are 6 things people get wrong about additives in tequila. First, only brands are confirmed additive-free by Tequila Matchmaker, not specific expressions, like Blanco, Reposado, and so forth.
Second, if a brand isn't on the Tequila Matchmaker list, it does not mean that that has additives. There's like 2,000+ tequila brands. The staff at Tequila Matchmaker can't possibly investigate every brand, and some brands don't want to be part of the program. And of course, many brands, of course, do have additives. Third, there is no foolproof way to test for additives unless you have a liquid chromatography setup lab. Yes, you can definitely train yourself to identify signature characteristics of additives, but it's hard to say for absolute certainty without a lab test. Fourth, there is nothing about additives required to be on any tequila label, which is unfortunate. Fifth, flavored tequilas cannot be confirmed as additive-free because the fruits used to make the flavors are, of course, a type of additive. And sixth, additive-free doesn't mean high quality. There are high-quality tequilas with additives and there are low-quality tequilas without additives. Additive-free is a production style and a commitment to authenticity, but by itself, it isn't a quality designation. Hope that clears some stuff up.