Kernels puff out and never shrink back to the first/best original density.  That is, the kernel is less dense after re-wet/dry.  K -State and other have data on that.   I do not know if wheat losses dry matter with re-wetting - my guess is as amylase activity increases that is a risk, never looked into it though. Wheat can take in moisture very quickly - and obviously can even sprout.  Corn sprout is rare in the north, but my understanding is unlikely after dry down (ie rarely re-wets enough) .