Hi Sigord, I know you asked this a while ago but thought I'd pick it up. To be honest, I don't know a huge amount about the particular type/brand of food you are feeding, and I'm not sure if there is such a thing as a vapour - it may just be that your cat likes to take their time with their dinner?!?! What I do know is that you will find it probably quite tricky to actually ever know for sure what is in the food as labelling in the UK tends to be a bit vague. I feed my cat, Mr Finley, food with fully declared ingredients so I know what he's having. The food contains lots of meat, offal and no added sugars or grains and he loves it. Maybe try these and see if the fussiness subsides?