Saffron (pronounced /ˈsæfrən/ or /ˈsæfrɒn/) is a spice derived from the flower of Crocus sativus, commonly known as the “saffron crocus”. Saffron crocus grows to 20–30 cm (8–12 in) and bears up to four flowers, each with three vivid crimson stigmas, which are the distal end of a carpel. The styles and stigmas, called threads, are collected and dried to be used mainly as a seasoning and colouring agent in food. Saffron, by far among the world’s most costly spices by weight, is native to Southwest Asia and was probably first cultivated in or near Greece. As a genetically monomorphic clone, it was slowly propagated throughout much of Eurasia and was later brought to parts of North Africa, North America, and Oceania.

Saffron’s taste and iodoform or hay-like fragrance result from the chemicals picrocrocin and safranal. It also contains a carotenoid pigment, crocin, which imparts a rich golden-yellow hue to dishes and textiles. Its recorded history is attested in a 7th-century BC Assyrian botanical treatise compiled under Ashurbanipal, and it has been traded and used for over four millennia. Iran now accounts for approximately 90% of the world production of saffron.

When saffron is dried after its harvest, the heat, combined with enzymatic action, splits picrocrocin to yield D–glucose and a free safranal molecule. Safranal, a volatile oil, gives saffron much of its distinctive aroma. Safranal is less bitter than picrocrocin and may comprise up to 70% of dry saffron’s volatile fraction in some samples. A second element underlying saffron’s aroma is 2-hydroxy-4,4,6-trimethyl-2,5-cyclohexadien-1-one, which produces a scent described as saffron, dried hay-like. Chemists find this is the most powerful contributor to saffron’s fragrance, despite its presence in a lesser quantity than safranal. Dry saffron is highly sensitive to fluctuating pH levels, and rapidly breaks down chemically in the presence of light and oxidizing agents. It must, therefore, be stored away in air-tight containers to minimize contact with atmospheric oxygen. Saffron is somewhat more resistant to heat.

The various saffron crocus cultivars give rise to thread types that are often regionally distributed and characteristically distinct. Varieties from Spain, “Creme”, is generally mellower in colour, flavour, and aroma; Italian varieties are slightly more potent than Spanish. The most intense varieties tend to be Iranian. Various crops are available from New Zealand, France, Switzerland, England, US; Dutch saffron—known for its “earthy” notes—is marketed in small quantities.

Almost all saffron grows in a belt from Spain in the west to India in the east. The other continents, except Antarctica, produce smaller amounts. In 2014, 250 t (250,000 kg) were produced worldwide. Iran is responsible for around 90–93% of global production, and much of their produce is exported. A few of Iran’s drier eastern and southeastern provinces, including Fars, Kerman, and those in the Khorasan region, glean the bulk of modern global production. In 2005, the second-ranked Greece produced 5.7 t (5,700 kg), while Morocco (the Berber region of Taliouine), and India (Kashmir), tied for third rank, each producing 2.3 t (2,300 kg).

In recent years, Afghan cultivation has risen. Azerbaijan, Morocco, and Italy are, in decreasing order, lesser producers. Prohibitively high labour costs and abundant Iranian imports mean that only select locales continue the tedious harvest in Austria, Germany, and Switzerland—among them the Swiss village of Mund, whose annual output is a few kilograms. Microscale production of saffron can be found in Australia (mainly the state of Tasmania), China, Egypt, parts of England France, Israel, Mexico, New Zealand, Sweden (Gotland), Turkey (mainly around the town of Safranbolu), the United States (California and Pennsylvania), and Central Africa.

Saffron prices at wholesale and retail rates range from USD $500 to USD $5.000, – per pound, or €1.000, – to €9.500, -/kg. In Western countries, the average retail price in 1974 was $1.000, – per pound, or € 1.900, – per kilogram. In February 2013, a retail bottle containing 0.06 ounces could be purchased for $16, – or the equivalent of USD $4.400, – per pound or as little as about $2.000, -/pound in larger quantities. A pound contains between 70,000 and 200,000 threads. Vivid crimson coloring, slight moistness, elasticity, and lack of broken-off thread debris are all traits of fresh saffron. As reference for comparison; Gold prices are in 2017 approximately: USD $ 20.000, -/pound or € 35.000, -/kg.