Dark red threads of saffron are often used to impart a rich yellow color and distinct flavor to traditional Spanish paella, French bouillabaisse, and other dishes. Known as the most expensive spice in the world, saffron is harvested just three delicate stigmas at a time from the purple flower of the saffron crocus (Crocus sativus). Producing just one pound of saffron requires hundreds of thousands of stigmas, thousands of flowers, and hundreds of hours of meticulous labor. While most recipes thankfully call for just a pinch or less, discerning cooks know that saffron's ability to color and flavor food can be enhanced by first steeping the dried threads in hot water or soaking them in alcohol. This important step helps to coax even more of the yellow-producing carotenoid, crocin, and other coloring and flavoring substances from within the dark red threads.