Is it safe to eat cheese after it has spoiled?

Opinions are divided around the world on whether it is safe to remove mold from cheese and continue eating it afterwards, as there is no clear answer to this age-old question.

But now an NHS doctor has finally put an end to the problem, although his answer may not please everyone.

The answer depends on the type of cheese in question and how widespread the mould is, says Dr Karan Rajan, a lecturer at the University of Sunderland. “Can you remove mould from cheese and still eat it? Yes and no,” he explains on TikTok. “The visible mould you see on food is just like the tip of an iceberg. You can’t see what’s underneath.”

According to Dr. Rajan, hard cheeses like cheddar, parmesan, and Swiss may be safe to eat even if they are moldy, provided you follow certain guidelines. First, it’s important that only “a small colony” of mold grows on the surface. If the cheese is full of germs, don’t hesitate to throw it away.

Secondly, consumers should leave a 2.5cm “safety margin” around the mold in all directions. This is mainly because mold roots can penetrate cheese up to 2cm deep, even if they are completely invisible to the naked eye.

This cheese cutting margin only applies to hard cheeses, Dr. Rajan continued. “Soft cheeses like feta, ricotta or cottage cheese that are sliced, crumbled or shredded and show mold should be discarded,” he explained. “Soft cheeses have a higher water activity, which means harmful bacteria can grow alongside the mold.”

Although rare, eating moldy cheese can lead to severe allergic reactions, diarrhea, vomiting, and even shortness of breath.

However, if you’re wondering why you can eat blue cheese, which is made from Penicillium mold, Dr. Rajan has the answer. He explains that unlike typical spoiled mold, blue cheese with added Penicillium is generally produced in controlled environments and does not produce any harmful toxins.

As a result, they are safe to consume. “There is no 100% guarantee that you will get seriously ill if you eat mold, it is just a risk reduction measure,” he continued. “Not all cheeses are made with mold, and not all molds are edible, especially if the mold is spoiled and not part of the original cheese-making process, as is the case with blue cheese or brie. Even if you heat moldy cheese, it will not destroy the mycotoxins produced by the mold.”