In the classic British comedy Absolutely Fabulous Edie Monsoon’s straight but exotic looking daughter is called Saffron, played by Julie Sawahla, who is partly of Jordanian ancestry. Jordan, as it happens is rather close to middle of the suite of cuisines that include saffron as a prominent spice. The use of saffron extends from Spain (probably thanks to the Moors) and Morocco on the west to India on the east. It has a hay-like fragrance and a mildly bitter taste and turns rice and other foods a golden color when cooked.
The spice is derived from the stigmas of a crocus called Crocus sativus. This is a tripolid plant (three copies of its chromosome complement in each cell) and therefore sterile. It is unknown in the wild and has been cultivated for thousands of years in Greece and the Middle East. The next generation of plants is produced by splitting the corms at the end of the harvest.
The growing of C. sativus is a labor-intensive form of agriculture. No plowing is done; everything is done by hand from the planting, through the tending to the harvest and collection and splitting of the corms. This is the principle reason that saffron is the most expensive herb you are likely to buy, costing $1,500 per pound or $6 to $8 per gram.
The stigma is part of the female organs (gynoecium) of the crocus flower. In the case of C. sativus these stigma are thread-like and bright scarlet and emerge prominently from between the petals. Because these are monocots in the Liliales order there are only three stigmas per flower. That is, it takes a lot of flowers to produce a small amount of saffron. There are 200 to 300 threads (stigmas) per gram of the spice. It takes 150,000 plants to produce 1 kilo of saffron.
C. sativus is an autumn blooming variety (like the familiar Colchicum autumnale, which is sometimes called meadow saffron) and so the harvest is in late fall, generally in November in Greece. It is thought to have been derived from C. cartwrightianus, which is known in the wild on the island of Crete. Sometime in the Bronze Age a mutant plant was apparently preserved and propagated vegetatively. From this eastern Mediterranean epicenter cultivation spread both east and west. Today commercial production still exists in Greece but it is very much rivaled by growing in Spain, Iran (the largest producer by far), and India.
As a commercial product saffron comes in many grades and two forms, threads and powdered. The threads are universally regarded as superior because they retain more flavor longer and are less likely to be adulterated. Probably because of its expense, there are plenty of sites on the Internet that coach you on how to identify good saffron. Vanilla Saffron Imports provides three basic criteria: (1) Saffron threads are all red (no other color). (2) Saffron threads must be dry and brittle to the touch. (3) Saffron aroma is strong and fresh, never musty. (Emphasis is theirs.) Nuances include noting the uniformity of the red color; if it is too uniform along the entire length of the thread, then it is more likely to have been dyed. Likewise any sign of abrupt banding suggests dying while one thread was lying across another.
Vanilla Saffron Imports touts the virtues of Sargol Saffron, which is grown in Iran and Afghanistan. One of the economic sanctions presently on Iran embargoes the import of their saffron into the U.S., so Vanilla is bringing it in from Afghanistan at present. Sargol saffron is cut and the stigmas separated from the rest of the plant before drying. It is therefore the most potent version of the spice. Vanilla implies that if the package is not labeled “Sargol,” then it may include other parts of the plant.
The redness of saffron is caused by a carotenoid called crocin. Its aroma is caused by a glucoside called saffranal and its taste by a carotenoid called picrocrocin. Rest assured it is a lot more complicated than this when you look at the chemistry and consider the changes that take place during drying and then cooking. All of these compounds are very sensitive to oxidation in the presence of light and oxygen, so saffron should be stored in a dark place in an air tight container.