being such an expensive spice it is often faked by dying threads red colour and there is an easy way to check this, add ice cold water to the filaments and see that on adding that no sudden rush of red fills the water, this will just be red paint immediately running out of the fake filaments. What to look for in real saffron is a yellowish gold colour slowly is released from the filament, within a second this will start to happen in the ice cold water, it will gradually make the entire water a golden orange colour, you can see here in this video a great way to test for pure saffron so you can have more detailed knowledge from watching this useful practical. The strongest cut in Iran is called sargol saffron and this is the tip 3mm of the filament which is all red, no orange from the mid section simply pure red where the highest concentration of chemicals naturally occur in this part of the flower. here is a trusted UK based online shop where to buy saffron safely.