A while back I got some froze fish from Costco in a bag. It was called codfish. I took it out and unfrosted it in the icebox for 24 hours like they said. When I cooked in the way a always do which is to pat dry, flour it, shake that off and then dip in egg and then into breadcrumbs and fry. It looked great smelled great but the inside the closer you go to the middle it got tough. They were pretty think slicec but shoulda been cooked through. Why were they tough. Never had that happen before. It was wild cod. Used it before and none of this happends.