Saffron is the stigma of the Crocus sativus flower. The stigma is the female part of the flower. Each flower produces three stigmas that are hand picked and dried. Because the stigma are so small, and must be hand picked, saffron is the most expensive spice on the market.
The best saffron uses only the upper bright-red stigma of the crocus flower. Lower grades will add the yellow style, which has no flavor. The lowest grades may be made of only the style. Good saffron should be bright red in color, never yellow.
In order to release the color, flavor and aroma of the saffron stigma it must be steeped for at least 20 minutes. Longer steeping releases more of the desired chemicals. Powdered saffron has the advantage of not needing to be steeped. It can be used as-is in the dish in the last few minutes of cooking, releasing all of its desired color, flavor and aroma immediately.
Saffron is popular in Iranian, Indian, Arab, Asian, European and Moroccan cuisines. Popular dishes that use saffron are Paella Valenciana, Italian Risotto alla Milanese, French Bouillabaisse and Cornish Saffron Buns. Saffron rice is popular in many cultures including Indian, Iranian and Spanish.