Almost every saffron on the market calls itself premium. It's not a protected term, so it costs a seller nothing to print it on a label. ISO 3632 Grade I is different: it's a specific, lab-tested number that means the same thing whether the saffron came from Spain, Iran, or Kashmir. Knowing what that number actually requires is the fastest way to tell a real quality claim from a marketing one.
Why a global standard exists at all
ISO, the International Organization for Standardization, sets comparable benchmarks across industries, from automotive safety to food packaging. It first published a saffron-specific standard in 1980, later splitting it into the ISO 3632-1/-2 pair still used today, with revisions since in 2003, 2011 and 2025. ISO's own material on the standard is candid about why it exists: saffron's high value has long made it "the object of frequent adulteration," and without a shared measure, quality claims from one country of origin were never really comparable to another's. A Certificate of Analysis showing a genuine Grade I result means the same thing everywhere, which is precisely the point.
Why this is different from Negin, Sargol, or Pushal
If you've shopped for saffron before, you may have seen names like Negin, Sargol, or Pushal. These are regional, visual classifications, describing thread length and how much of the yellow stigma base was trimmed off. They're a real and useful part of how saffron is traditionally sorted, but they describe what saffron looks like, not what it actually contains.
That distinction matters in practice, not just in theory. A 2018 study testing Iranian market grades against ISO 3632 found the mapping isn't guaranteed: one commercial grade, sorted the traditional way by appearance, didn't meet any ISO category at all, despite being a real, sold product. Visual sorting and instrumental grading are measuring different things, and only one of them is checked by a spectrophotometer rather than an eye.
What Grade I actually requires
The test reads a dissolved sample at three wavelengths: 440nm for crocin (colouring strength), 257nm for picrocrocin (flavour strength), and 330nm for safranal (aroma strength). To be classified Category I, the top of the traditional scale, a sample needs a colouring strength of at least 190, a flavour strength of at least 70, and an aroma strength between 20 and 50. Fall short on any single one of the three and the whole batch drops a grade, no matter how it looks or smells on its own.
This is also why we don't ask you to take Grade I on trust. RedGold88™ Extract is made from the same ISO 3632 Grade I saffron sold as Reserve Threads, independently tested by Eurofins UK, with a crocine (colour strength) value of 241, well clear of the 190 minimum. That Certificate of Analysis is published on the product pages, not just referenced in copy.
What to ask before you buy saffron anywhere
A seller can call their saffron premium, top-grade, or Grade A with no test behind any of it. The one question worth asking is simple: can they show you an actual ISO 3632 Certificate of Analysis, with the crocin, picrocrocin, and safranal figures on it, not just a grade printed on the packaging. If they can't produce one, the grade claim isn't verified, whatever the label says.
Two ways to buy saffron that's actually tested
If you're taking saffron for mood, calm, or sleep, RedGold88™ Extract concentrates crocin and crocetin into a standardised 50:1 dose, tested to Grade I in every batch. If you're cooking, Reserve Threads gives you the same Grade I standard in whole, unground threads, so you can see exactly what you're using. Both come with the lab result to prove it, not just the claim.