Saffron should be soaked for a minimum of 20 min and up to 12 hrs. or overnight in a little warm water before cooking.
Saffron continues to release its flavor for up to 12 hours after cooking, which is why it is seen as important to soak the saffron strands before cooking. Soaking
Soaking or steeping saffron helps to release its full flavor before cooking, in this way less may be needed to achieve the same desired taste.
The highly soluble properties of saffron mean that it can be soaked or steeped in a wide variety of liquids, at a range of temperatures.
It can be steeped in hot or temperate water, broth, milk, white wine, white vinegar, vodka, citrus juice, and even flavored waters such as rosewater or orange blossom water.
This is one method, but not the absolute rule – saffron is often dried and then crushed with a mortal and pestle.
It is often thrown directly into the pot when time is short, whenever there is an extended cooking process, or when desired.