Scottl, thanks for your answer. I’ll definitely try barley coffee. I live in Russia BTW 
I found out recently it is drunk a lot in Italy where it’s called orzo coffee. If you google that you see you can get all sorts, including ground for cafetieres. Worth a go anyway!
Hi all, a cup of decaf has approx. 10 mg of caffeine. Some 6, some 12, and of course it depends on the size of the ‘cup’ :))