I'm now kind of upset at myself that I have thrown out perfectly good Cheddar in the past due to white spots.
replies(4):
For firm & hard cheeses, the bad molds very rarely penetrate the surface. If you get some questionable looking mold on the outer surface, you can cut off the outer couple of mm and enjoy the remainder just fine. For rustic/home made cheeses, handling the "bad" mold on the outer surface is a normal part of the aging process before it makes it to the customer anyway. https://cheesemaking.com/blogs/learn/how-to-bandaging-chedda...
The USDA says to cut off at least an inch and be careful not to cut through mold: https://www.fsis.usda.gov/food-safety/safe-food-handling-and...