Trade and use of saffron Church in Pennsylvania. In recent decades cultivation has spread to New Zealand, Tasmania, and California. Iran has accounted for around 90–93 percent of recent annual world production and thereby dominates the export market on a by-quantity basis. Almost all saffron grows in a belt bounded by the Mediterranean in the west and mountainous Kashmir in the east. All other continents except Antarctica produce smaller amounts. In 1991, Some of whole threads and powder are gleaned yearly, of which is top-grade "coupe" saffron. Iran is by far the world's most important producer: in 2005 it grossed some of dry threads, or
Saffron per gram, given the wide possible range of colouring strengths that different kinds of saffron can have. Despite attempts at quality control and standardisation, an extensive history of saffron adulteration, particularly among the cheapest grades, continues into modern times. Adulteration was first documented in Europe's Middle Ages, when those found selling adulterated saffron were executed under the "Safranschou" code. Typical methods include mixing in extraneous substances like beetroot, pomegranate fibres, red-dyed silk fibres, or the saffron crocus's tasteless and odourless yellow stamens. Other methods included dousing saffron fibres with viscid substances like honey or vegetable oil to increase their weight.