1. Choose by origin
Saffron grows in Iran, Spain, India (Kashmir) and Italy in large quantities. Your major purchasing decision will be country of origin. When you can find Iranian saffron, that would be your top choice. The color is a deeper red and spice’s telltale musk (a fantastic corrective to its sweet perfume) is more pronounced. The next step down (though only the nitpickiest would call it a downgrade) is Spanish saffron, which is high quality, relatively available, and strictly regulated.The quality of saffron declines for Italian and Indian saffron however it can be much cheaper.
2- Check the color
High quality saffron threads will appear dark red – the redder, the better. There should be no colour variation. If the yellow style can be viewed, it means that it hasn’t been removed and while it has no culinary benefit.
3- Check the smell
It should smell sweet, with a floral-type aroma.
4- Always choose thread over powder
powdered saffron ten to have more yellow threads since it is not noticeable hence it often has lower quality.