Saffron grades and ISO 3632: how to judge Iranian saffron

Where Iranian saffron comes from

Iran grows the largest share of the world's saffron. Most of it comes from Razavi Khorasan and South Khorasan provinces in the east, around Torbat-e Heydarieh, Gonabad and Qaen, with smaller areas in other provinces.

Saffron is the dried stigma of the Crocus sativus flower. The flowers are picked by hand during a short harvest that usually runs from late October to late November, and the red stigmas are separated and dried soon after. Each flower gives three stigmas, which is why saffron is sold by the gram.

The six-digit HS code for saffron is 0910.20; check the full code with your customs broker.

ISO 3632: the three categories

ISO 3632-1 sets the specification and ISO 3632-2 sets the test methods. The key values are measured by UV-Vis spectrophotometry on a water extract of the saffron and expressed as E1% 1cm, the absorbance of a 1 percent solution in a 1 cm cell, on a dry basis.

The table shows the minimums for dried filaments in ISO 3632-1:2011. Check the current edition of the standard before you write a contract, because standards are revised. The standard also sets limits for floral waste (yellow style) and extraneous matter, which are stricter in Category I.

Crocin, picrocrocin and safranal in practice

Crocin is the main driver of price. In trade it is often quoted simply as colouring strength, for example 'crocin 250'. Much Iranian export saffron of the all-red cuts tests well above the Category I minimum, and buyers in food manufacturing often specify a minimum crocin value higher than 200.

Picrocrocin gives saffron its bitter-honey taste and is the precursor of safranal. Safranal is the main aroma compound; the standard sets a range rather than a minimum, because unusually high values can point to heat damage or poor drying.

Moisture affects both price and shelf life. Saffron is sold by weight, so extra water means you pay for water, and moist saffron loses colour and aroma faster.

Iranian trade names: the cut of the thread

Trade names describe which part of the stigma is in the pack and how it was trimmed. They are not defined by ISO 3632, and suppliers do not always use them in exactly the same way, so attach photos and a lab specification to every order.

How trade name and ISO category relate

All-red cuts (Super Negin, Negin, Sargol) usually test higher in crocin than Pushal or Dasteh, because the yellow style has little colour. But a cut name does not guarantee a category. A well-dried Sargol can test Category I, and a poorly dried or old Negin can fall below it.

For that reason a sound specification reads like this: cut Negin, ISO 3632 Category I, crocin minimum stated, moisture maximum stated, crop year stated, with a lab report from the exporting lot.

How to read a saffron lab report

• Check the standard named on the report: it should say ISO 3632-2 for the test method
• Check the units: crocin, picrocrocin and safranal should be E1% 1cm values on a dry basis
• Compare each value with the category claimed on the label and with your contract minimums
• Check moisture, floral waste and extraneous matter, not only colour
• Check that the lot number and sample date match the lot you are buying
• Check that the laboratory is accredited, ideally to ISO/IEC 17025
• For food use in your market, ask for pesticide residue and synthetic dye results as separate tests

How to spot adulteration

Saffron is one of the most adulterated foods because of its high value per gram. The common methods are adding weight (oil, glycerine, sugar or honey solutions, or extra moisture), mixing in dyed saffron style or other plant parts such as safflower petals or corn silk, and adding synthetic dyes. Powder is easier to adulterate than threads.

Simple checks help but do not replace a lab. Real saffron threads release a yellow-gold colour slowly in water while the thread itself stays red; a thread that turns pale quickly while the water turns red points to dye. Real threads feel dry and brittle, not oily or sticky.

For a reliable answer, ask the lab for ISO 3632 values plus a test for synthetic water-soluble dyes, often done by HPLC. Buy threads rather than powder for a first order, and grind locally if you need powder.

• Threads look glossy, feel oily or stick together
• Threads are all the same length, with no natural trumpet shape at the top
• Water turns red or orange at once
• Lots of yellow or white pieces in a pack sold as all-red
• Crocin claim far above every other lot of the same crop year

Packaging, storage and shelf life

Saffron must be kept away from light, air, moisture and heat. Bulk export saffron is usually packed in sealed tins or foil-lined bags inside cartons, often in 100 g, 500 g or 1 kg units. Retail packs range from 0.5 g and 1 g to the traditional mithqal of about 4.6 g, in tins, glass jars or acrylic boxes.

Stored airtight, dark and cool, saffron usually keeps its quality for about two to three years from harvest, losing colour and aroma gradually. Ask for the crop year on the label, because a fresh crop and a two-year-old crop of the same cut are not equal.

Because it is high-value and light, saffron usually travels by air. See /guides/shipping-routes-from-iran.

Buying graded saffron on ASL Market

Browse saffron listings at /buy/iranian-saffron-wholesale, or post a buying request at /post-request with the cut, ISO 3632 category, minimum crocin, maximum moisture, packaging and quantity. Ask suppliers in chat for the lab report of the actual lot; messages go through ASL Market and contact details stay private.

The supplier confirms price, quantity, freight, Incoterm and ship-by date. You pay in USDT and ASL Market holds the payment until you confirm receipt, so you can test the delivered saffron before releasing payment; see /trade-assurance. Import rules differ by country; check your own country's rules on trade with Iran before you order.

FAQ

What is ISO 3632 Category I saffron?

It is saffron that meets the highest of the three categories in ISO 3632-1. For dried filaments in the 2011 edition, that means crocin of at least 200, picrocrocin of at least 70 and safranal between 20 and 50, measured as E1% 1cm on a dry basis, with moisture of no more than 12 percent.

What is the difference between Sargol and Negin?

Both contain only the red part of the stigma. Negin threads are longer, thicker and more carefully trimmed, while Sargol consists of the red tips, which are shorter and include some broken threads. Lab quality depends on the lot, so ask for the ISO 3632 values of each.

What is Pushal saffron?

Pushal is red saffron stigma with a short piece of the yellow or orange style attached. It usually has lower colouring strength per gram than all-red cuts, because the style adds weight but little colour.

Which saffron grade has the most colour?

The all-red cuts, Super Negin, Negin and Sargol, usually have the highest crocin values. The actual value depends on the crop, drying and storage, so compare lab reports rather than names.

How can I tell if saffron is fake?

Warning signs include oily or sticky threads, threads of uniform length with no trumpet-shaped tip, and water that turns red immediately. A lab test to ISO 3632-2 plus a synthetic dye test gives a reliable answer.

How long does saffron keep?

Stored airtight, dark, cool and dry, saffron usually keeps its quality for about two to three years from harvest. Colour and aroma decline gradually, so ask for the crop year.

When is the Iranian saffron harvest?

The harvest usually runs from late October to late November. New-crop saffron typically becomes available for export after drying and packing in the following weeks.