Digging into the depths of your fridge can sometimes be a gamble. Along with that half-eaten head of cabbage – which has surprisingly lasted longer than some relationships – could be that block of cheddar you recently bought but has grown a patch of mould overnight. Can you salvage it? Are you setting yourself up for a trip to the ICU? Is it safe to eat mouldy cheese?

For hard and semi-hard cheeses like Cheddar, Gouda and Parmesan, it’s generally safe to cut off the mouldy part and consume the rest.

Mouldy or Just Matured?

We’ve all been there. It’s a common dilemma and is often met with the thought that ‘cheese is mould,’ so it stands to reason that you could just shave off the mouldy bit and get on with making your grilled cheese, but the cheese-mould conundrum is slightly more complex…

Stilton, Gorgonzola, Roquefort – if these visibly mouldy varieties are the highlight of your cheese board, that compromised bit of gouda in your fridge should be safe to eat, right? I say the stinkier and mouldier, the better, but that’s not always the case.

While cheese requires bacteria to produce, new-forming isn’t always safe to consume. Certain moulds and bacteria are considered safe and are used in cheese production. These include Penicillium roqueforti (used in blue cheeses), Penicillium candidum (used in Brie and Camembert), and Lactobacillus and Streptococcus – these beneficial bacteria are also used in cheese fermentation.

Can I Eat Mouldy Cheese?

Blue cheeses such as Roquefort, Gorgonzola and Stilton are intentionally inoculated with specific moulds during cheese production. Brie and Camembert lovers might be surprised to learn that the white exterior, which protects the melty cheese inside, is made from mould.

That’s right – similar to hairy tofu, beneficial bacteria (Penicillium candidum) are carefully controlled and contribute to the unique flavours and textures of cheese like brie and Camembert. Unlike the black or green mould that forms on soft cheese that is not meant to be aged, this white, bloomy rind is safe to eat. The same goes for veiny, blue cheese and hard cheeses like Parmesan and Grana Padano. The only difference is that the mould is usually confined to the surface and can be removed, while the interior remains unaffected.

If you’re not a microbiologist or cheesemaker, distinguishing between these types of bacteria might prove difficult, but there are ways to cut corners (and rinds).

For hard and semi-hard cheeses like Cheddar, Gouda and Parmesan, it’s generally safe to cut off the mouldy part and consume the rest. Just make sure to cut generously and inspect the cheese before you grate it over that mac and cheese.

 The moulds that grow on these cheeses are typically environmental contaminants, and their safety can be questionable.

Simply remove about 2.5 cm around and below the mouldy spot. Be careful not to let the knife touch the mould to avoid cross-contamination. Next, ensure that the cheese looks and smells ‘normal’ after cutting away the mould. You might be wondering…

What About Soft Cheese?

For soft cheeses, it’s best to discard the entire cheese if mould is present, as it can easily spread throughout the cheese. Especially if the bacteria present as green and black spots – steer clear of these types – intentionally inoculated blue cheese is the only exception!

Mould formation on cheeses such as Cheddar, Gouda and Mozzarella, which are not intentionally inoculated can be problematic. The moulds that grow on these cheeses are often environmental contaminants, and their safety can be questionable. Common moulds found on these cheeses like Aspergillus can produce harmful mycotoxins. While some Penicillium species are safe to consume, other types can produce harmful substances.

The safety of eating mouldy cheese depends on several factors, including the type of cheese and the specific mould. Some moulds are harmless or even beneficial, while others can be dangerous to your health. Even if you think you have a ‘strong stomach,’ you should always err on the side of caution!

Cheesy Recipes You’ll Love

Pork Meatballs with Bocconcini & Spicy Arrabbiata
Chakalaka Mozzarella Skillet Melt

Mushroom Ragu on Parmesan Polenta
Biltong, Caramelised Onion & Blue Cheese Tartlets

Fond of fungi? Learn how to cook different types of mushrooms.