Firstly for excellent quality ensures that the saffron has only bright red stigmas (red filaments) and no other part of saffron flower find way into the pack. That means no style (the yellow part) or any foreign matter.
The style (i.e. yellow part) of the plant has no culinary value that means no aroma, flavor or color. If left attached to red stigmas, it adds dead weight to the saffron and the customer pays for it.
Dryness (Moisture Not Be Beyond 4-5%) Saffron filaments (stigmas) must be dry and brittle to touch. Any presence of moisture beyond 4-5% only adds extra weight. It lowers the quality and shortens the shelf life of Saffron.
The aroma of saffron is strong and fresh, never musty.