The USDA offers detailed guidance on how to handle cheese with mold on it. For hard cheeses where the mold is not part of the processing, cut at least 1 inch around and below the mold, taking care not to drag the knife through the mold and cross contaminate the rest. Cover the cheese in fresh wrap, and you’re good to go.
For soft cheeses made with mold, such as blue, brie and Camembert, discard any that sport mold that is not part of the cheesemaking process. You’ll be able to tell the difference on soft, ripened cheeses, according to Saxelby, because the rind may look yellow, brown, grayish or slimy, rather than the original white. If there’s atypical surface mold on a mold-processed hard cheese, such as Stilton or Gorgonzola, use the same advice for hard cheese above.
Do not eat soft cheeses (cottage, cream cheese, chevre) with mold, the USDA advices, because they can be contaminated below the surface. The same goes for sliced, shredded or crumbled cheeses, the contamination of which can be hard to discern.