How does dehydration affect osmolarity?
Well, you are increasing the osmolarity of the stuff that is dehydrated......
And have you ever eaten dried fruit.....? Of course you have. You eat raisins and sultanas and prunes, and these are MUCH sweeter (i.e. greater sugar concentration) than the fresh fruit. When you soak sultanas/raisins/currants in water, the fruit takes in water to get reconstituted and plump