According to the National Pork Board, the best way to thaw frozen pork is in the refrigerator in its original wrapping. For a large roast, thaw for 4 to 7 hours; for a small roast, thaw for 3 to 5 hours. For pork chops, thaw for 12 to 14 hours, and for ground pork, simply estimate based on package thickness. You may also defrost pork in the microwave. Simply follow your manufacturer′s guidelines for defrosting meat, and be sure to cook the pork immediately after thawing.