Thanks Jerry and CA for the input much appreciated 

thanks for that ss, will bear it in mind. I have a mixture of whole and ground in stock and can get what i need without too much bother living in bradford 

Ooo first post.Been lurking here a while.This has puzzled me a bit too. I guess it gives a better result but is it absolutely necessary to dry roast before grinding for use or can you just grind the coriander seeds say, straight out of the packet for an acceptable result ?