Saffron is the most expensive spice in the world by weight, and the one most often sold short. A little knowledge goes a long way at the counter.
Look at the thread
A good thread is deep red with a slightly flared trumpet at one end. Pale yellow or white streaks mean the style has been left on — that part carries no flavour and no colour, and you are paying saffron prices for filler.
Trust your nose
Real saffron smells sweet and hay-like, a little medicinal. If a sample smells of nothing much, it has been sitting in the light too long.
The water test
Drop a few threads into warm water. Real saffron releases its colour slowly, over ten or fifteen minutes, and the threads keep their red. Dyed safflower bleeds colour immediately and goes pale.
Storing it
Airtight, dark, and away from the hob. Saffron does not spoil, but it fades. Bought well and stored properly, a gram will outlast the year.
