The first and easiest way to tell pure saffron from the adulterate one is noticing the ISO certificates. ISO 3632-1 and ISO 3632-2 are the specific standards that testify saffron’s taste, fragrance and colour as well as lack of any chemical toxicity.
The following table shows saffron’s properties according to ISO 3632:
Moreover, saffron’s physical appearance is another way to assess its quality. Real saffron is round on one end and more flat with smaller dents on the other end. Additionally, saffron’s colour is sharp crimson not light red. Furthermore, saffron threads must be separate and not stuck together in bundles. Usually when they are stuck together, it means they are sprayed with soda or salt water to gain extra wight.
Extra care should be taken when buying ground saffron. Sometimes ground saffron is mixed with turmeric, sugar or salt to add extra weight. In this case, although it gives a yellow colour, it lacks the usual saffron taste.
Adulterated saffron can contain artificial colours such as tartrazin orange, amaranth, sunset yellow, quinoline yellow and azorubine. Other impurities include fibre, sand, insects, fungi and other pollutions.