Discovering a green or blue mold spot on cheese doesn’t always mean the entire block must be thrown away. The right decision depends mainly on the type of cheese and how easily mold can spread through it.

Some cheeses, including blue cheese, Roquefort, Stilton, and Gorgonzola, are intentionally made with controlled mold cultures. Unexpected mold on other cheeses, however, requires more caution.

Hard cheeses such as cheddar, Parmesan, Gouda, and Swiss are dense and contain less moisture. Mold is less likely to spread deeply through them, so a small affected area can often be removed safely.

Food-safety recommendations generally advise cutting at least one inch (2.5 centimeters) around and below the visible mold. Use a clean knife and avoid letting the blade touch the mold before cutting into the remaining cheese.

Soft cheeses are different. Cream cheese, ricotta, cottage cheese, Brie, Camembert, and fresh mozzarella contain more moisture, allowing mold and potentially harmful bacteria to spread beyond the visible area.

For this reason, the safest recommendation is to discard soft cheese when unexpected mold appears. Removing only the affected portion cannot reliably eliminate hidden contamination.

Another concern is mycotoxins, substances produced by certain types of mold. Not all molds produce them, but consumers generally cannot identify the species simply by looking at its color. People with weakened immune systems should be particularly cautious.

Smell and appearance are not reliable ways to determine whether contaminated cheese is safe. Some spoiled products have obvious odors, while others may look and smell relatively normal. Mold color alone also cannot establish whether it is dangerous.

Proper storage helps prevent unwanted mold growth. Keep cheese refrigerated, wrap it appropriately, use clean utensils, and avoid leaving it at room temperature for extended periods. Different varieties may require different packaging to maintain the right moisture balance.

Ultimately, the simplest rule is to remember the difference: a small mold spot on hard cheese can often be cut away generously, but unexpectedly moldy soft cheese should be discarded. When in doubt, throwing it away is the safer choice.