The stigma of a type of crocus, saffron threads have a pungent and distinctive aroma and flavour - slightly bitter, a little musty, and with a suggestion of something floral.
It's a labour-intensive crop, which means that saffron commands a high price; each crocus produces just three stigmas, which are hand-picked and then dried, and it takes thousands of stigmas to make just one ounce of the spice. Happily, the flavour is better if you use just a little - too much, and it tastes too bitter.
The main saffron-growing countries are India, Iran, Spain, Greece and Italy, although it was once grown in Saffron Walden, Essex, hence the town's name.
All year round.
Choose the best
As a rule of thumb, the deeper the colour of the threads, the better the quality. Deep red with orange tips is considered to be the best. If the tips aren't orange it might indicate that the saffron is inferior and has been dyed.
Inferior saffron can also look slightly frayed and worn. If you're buying saffron in markets abroad, beware of cheap deals - the real thing is always expensive. Avoid anything that's too yellow, as it is probably a fake. You can also buy ground saffron, but it loses its potency quite quickly and is sometimes adulterated with other ingredients.
To draw out the colour and to ensure that it's evenly distributed throughout the dish it's to be added to, steep saffron threads in a little warm water, stock, milk or white wine for about 30 minutes before using. Then add the liquid to the dish, usually towards the end of cooking. If you like, you can strain the threads out before you add the liquid, but it's a fiddly job, and the threads look good in any case.
In an airtight container in a cool, dark place. It will keep for several years.
In Spanish paella, French bouillabaise or Italian risotto Milanese. Use in baking, or add to tomato sauce. Add to the water when making rice.