Barley as a thickener in soups

I made a pumpkin soup thickened with barley (rather than potatoes) a couple of days ago but haven't yet got the proportions right.  I used too much barley so it was a bit too thick and slimy - more like a soupy risotto than a proper soup.  Barley behaves oddly once cooked too, in that it seems to go on getting more and more glutinous.  When I re-heated the leftovers 24 hours after cooking it, it had gone quite solid.

I'm not posting a recipe yet, but I'll have another shot at a similar soup some time in the next couple of weeks to see if I can make a better version.