QUALITY WITHOUT GUESSWORK
Look at the threads. Then look at the evidence.
Commercial grade names such as Super Negin can help describe appearance and positioning, but quality is stronger when observable characteristics are paired with measured evidence.
Three markers on the referenced certificate
Crocin is used as a measure of colouring strength. Picrocrocin relates to flavour strength, and Safranal to aroma strength. The displayed certificate for sample 004196 records Crocin 294.5, Picrocrocin 111.8 and Safranal 31.2.
The same document prints Class I thresholds of at least 200 for Crocin, at least 70 for Picrocrocin and 20–50 for Safranal. Artificial colorants are recorded as absent for that sample.
The certificate states that its result applies only to sample 004196. This store therefore does not use it to claim automatic ISO certification for every future batch.
At home
Use appearance, aroma and how the threads release colour during blooming as practical observations, but do not treat a home water test as a substitute for laboratory testing or proof of authenticity.