Grade, origin, and the number on the sticker

Saffron is the dried stigma of Crocus sativus. Each flower gives three. The red portion is the stigma. The pale tail is the style. Some packers trim the style away. Some leave it on. A jar of trimmed red threads looks stronger in the palm and costs more per gram, because part of each flower was discarded. A thread with a yellow tip can be a complete stigma. Taste it. The style is milder.

The lab word worth asking about

The specification the spice trade uses is ISO 3632. A lab soaks a weighed sample and reads color, bitterness, and aroma on a meter. The pigments are the crocins. The bitter taste is picrocrocin. The aroma that develops as the fresh stigma dries is mostly safranal. The spec sorts the results into categories, and Category I is the top color class in that system.

You settle this at the table only in the crudest way: warm water, a white plate, your nose. The meter is a lab's job. A seller who prints ISO 3632 Category I is making a claim you can ask them to support with a sheet for that lot. A seller who prints premium, coupe, or super negin is using a market word. Those words point at a cut and a color, and they are applied differently from one country to the next. Ask which cut, in a sentence a cook can picture.

Origin is the other half of the sticker

Iran grows most of the world's saffron. Spain's La Mancha crop is small and sells under a protected regional name. Kashmir's crop around Pampore is small and often dear. Herat, in Afghanistan, is the origin named by both shops this suite links to. A country or a province is the start of a question. A region can pack a careful harvest or a tired one.

• Use the gram price to compare two whole-thread jars of a similar cut.
• Use a real lab grade, when the seller can show it, to compare strength.
• Use your nose for the rest. Crush one dry thread. You want hay, honey, and a cool floral edge.
• A jar with no smell is either tired or something else. The grade on the website may describe a different day.

Compare the gram, the cut, and the smell. The word premium can sit on any of them.

How to look at a single thread, including the warm-water test and the usual substitutes, is the work of Saffron Threads. The history of why these regions ended up on labels is on Saffron History.