SEE ALSO: How can you tell when your cheese has gone bad? →

What is ammoniated cheese?

Ammoniated cheese is cheese that develops a distinct ammonia smell and taste. This happens due to the natural breakdown of proteins in the cheese. Ammonia is a by-product of this process, created by bacteria and enzymes during ripening.

Some cheeses, particularly bloomy-rind varieties like Brie and Camembert, are more prone to developing ammonia. Washed rind cheeses can also exhibit this trait. In small amounts, ammonia is normal and part of the cheese’s aroma profile.

However, when the ammonia smell becomes overpowering, it indicates a problem. The cheese may have ripened too much or been improperly stored. Eating it can be unpleasant due to its harsh taste and smell.

Why does cheese smell like ammonia?

The ammonia smell in cheese is part of its natural ageing process. Proteins in cheese break down over time, releasing ammonia as a by-product. This is more noticeable in certain types of cheese because of their rind and ripening process.

In bloomy-rind cheeses like Brie, the white mould (Penicillium camemberti) plays a role in the ripening. It breaks down proteins and fats, creating a creamy texture and unique flavour. However, this process also generates ammonia, which gets trapped under the rind if the cheese isn’t stored properly.

Washed rind cheeses, like Époisses or Taleggio, are another example. Their rinds are washed with brine, alcohol or other solutions to encourage bacteria growth. These bacteria also produce ammonia as they age, which can become overwhelming if the cheese over-ripens.

How can storage contribute to ammoniation?

Improper storage conditions can accelerate the ammoniation process. Cheese needs ventilation to allow gases like ammonia to escape. If cheese is wrapped too tightly in plastic or stored in airtight containers, ammonia gets trapped.

Temperature also plays a crucial role. Storing cheese at too warm a temperature speeds up bacterial activity. This leads to faster protein breakdown and more ammonia production.

When is ammoniation normal?

Some ammonia scent is normal in certain cheeses, especially those with a bloomy or washed rind. This is often more pronounced when the cheese is first removed from its packaging.

Allowing the cheese to “breathe” at room temperature for 15-30 minutes can help. During this time, the ammonia dissipates, and the cheese’s natural aromas become more noticeable.

However, if the smell remains strong or the taste is unpleasant, the cheese may have gone past its prime.

How to recognise ammoniated cheese

Here are signs your cheese may be ammoniated:

1. Strong ammonia smell: Overpowering and harsh, like household cleaning products.
2. Harsh taste: The flavour is bitter and unpleasant, masking the cheese’s usual characteristics.
3. Texture changes: Over-ripened cheese may become overly runny or break down entirely.

These signs indicate that the cheese has aged beyond its ideal eating window.

What to do with ammoniated cheese

If you notice a mild ammonia smell, let the cheese sit at room temperature for 15-30 minutes. This allows the gas to dissipate. Often, this is enough to make the cheese enjoyable again.

For more heavily ammoniated cheese, there’s little you can do to salvage it. The taste and aroma are unlikely to improve. If the cheese remains unpleasant after airing, it’s best to discard it. Consider composting your cheese waste to protect the environment.

Can ammoniated cheese make you sick?

Ammoniated cheese is not necessarily unsafe to eat. Ammonia itself is a natural by-product and not harmful in small amounts. However, the taste and smell can be unpalatable, making the cheese undesirable to eat.

If the cheese shows other signs of spoilage, like mould where it shouldn’t be or a sour smell, it’s better to throw it away.

How to prevent cheese from becoming ammoniated

Preventing ammoniation starts with proper storage. Follow these tips to keep your cheese fresh:

1. Use breathable wrapping: Avoid plastic wrap. Instead, use wax paper or cheese paper, which allow the cheese to breathe.
2. Store in the right spot: Keep cheese in the vegetable drawer or a dedicated cheese container in the fridge. These spots have consistent humidity and temperature.
3. Maintain proper temperature: Most cheeses do well at 2-7°C (36–45°F). Avoid storing them in areas prone to temperature fluctuations.
4. Don’t store cheese for too long: Each cheese has an ideal ripening window. Consume it within that time for the best flavour and texture.

Are some cheeses more prone to ammoniation?

Yes, certain types of cheese are more likely to develop an ammonia smell. Bloomy-rind cheeses like Brie, Camembert and Coulommiers are common examples. Their rinds trap gases during ripening, increasing ammonia concentration.

Washed rind cheeses, such as Munster, Limburger and Époisses, are also prone to ammoniation. Their bacterial rinds produce ammonia as they age.

Soft, ripened cheeses are more susceptible than harder varieties. Cheeses like Cheddar or Parmesan are less likely to become ammoniated due to their firmer texture and different ripening process.

When to consult a cheesemonger

If you’re unsure about the state of your cheese, a cheesemonger can help. They can advise whether the cheese is still good to eat or past its prime.

Cheesemongers can also provide tips on storage and how to enjoy cheese at its best. Building a relationship with a local cheesemonger ensures you get expert advice tailored to your preferences.

Conclusion

Ammoniated cheese is a natural but sometimes unpleasant result of the ripening process. While a slight ammonia smell is normal in some cheeses, an overpowering scent indicates over-ripening or poor storage.

Proper storage, including breathable wrapping and the right temperature, helps prevent ammoniation. If you encounter ammoniated cheese, airing it at room temperature may improve its aroma. For severely ammoniated cheese, it’s better to discard it.

Understanding the causes of ammoniation helps you enjoy cheese at its best. Treat cheese with care, and you’ll avoid unpleasant surprises.

Jonah Kincaid

Cheese lover. Scientist. Created a website and a Youtube channel about cheese science because he could not find answers to his questions online. 

cheesescientist.com

The post Ammoniated Cheese: What It Is & How to Prevent It appeared first on Cheese Scientist.

Mould is cheese

Mould can be scary if you’re not used to seeing it on food. But it can actually be an important part of cheesemaking. If you’ve ever wondered whether you can eat mouldy cheese, we’ve got all the answers to your questions below.

If you’ve eaten cheese even once in your life (I know you have, you wouldn’t be here otherwise), then you have eaten mould. Are soft cheeses your jam? Meet Penicillium candidum. Are you more of a blue cheese fiend, say hello to our little friend, Penicillium roqueforti. 

What moulds are safe to eat?

Picture this. You bought yourself a little treat the last time you were at your local cheese shop. A round of your favourite triple cream soft cheese, Brillat-Savarin. Today is the day when you get to dig into it! You’ve been waiting for this moment since you brought it home. You go to the fridge and pull it out.

Oh no, there is a patch of fuzzy mouldy growth on top of the rind! What do you do? Do not freak out! Read on to find out why this mould is perfectly safe to eat. Moreover, mould can be desirable in cheese.

Mould in cheesemaking

Mould is used for various reasons in the cheesemaking process. Some like Penicillium candidum and Geotrichum candidum add the beautiful white textures that we all love on the rind. Others like Penicillium roqueforti and Penicillium glaucum add the blue veins that we all go gaga over in blue cheeses. 

Cheese is a living organism

In summary, mould contributes significantly to the aroma, flavour and texture of the cheeses we love. Furthermore, think of both the mould and the cheese as living organisms.

When you keep cheese in your fridge, it breathes and lives and continues to grow. So does the good mould. So, it is not uncommon to find fluffy bunny tails growing on the surface of soft white mould cheeses. Or patches of blue on some hard cheeses. One great example of the latter is a gorgeous Cheddar from Wales called Hafod. 

What types of mould aren’t safe to eat?

However, there are some moulds that can be dangerous. The most common one is Aspergillus niger, a.k.a the Black Mould. This fungus will have a severe negative impact on the food product it contaminates and releases toxins in the body that can be harmful. Having said that, it is very rarely found on cheese.

Moreover, some other moulds can be a bit like an iceberg. You will only see a flat patch of greyish-blue or green on the surface of the cheese. The rest will lie under the rind.

Can mouldy cheese be eaten?

Also, remember that your fridge may not be a controlled environment and you do not really know what moulds are present. Therefore, we need some rules. The safest approach is to avoid eating any questionable mould. What you do with the rest of the cheese will depend on its moisture content and texture.

Cheeses you should discard

If it is fresh cheese (e.g. Ricotta, Queso Fresco, Cream Cheese) or pasta filata (e.g. Mozzarella, Stracciatella, Bocconcini), the best thing is to discard all of it. Those cheeses are high in moisture and quite soft. Because of this, the mould will have very likely penetrated all the way through. 

Cheeses you can save

On a more positive note, if it is a semi-hard (e.g. Comté, Gruyère, Emmentaler) to hard cheese (e.g. Cheddar, Gouda, Parmigiano Reggiano), the mould will most probably be only on the surface and can be sliced off. The rest of the cheese should be absolutely fine to eat. 

One last piece of advice

Do not leave cheese long enough in your fridge for it to develop contamination! Buy what you will eat within a week. One exception to this rule is if you are buying a whole wheel of cheese with a natural rind. Those will actually get better with time as you allow them to reach their “Best Before Date”.  

Jonah Kincaid

Cheese lover. Scientist. Created a website and a Youtube channel about cheese science because he could not find answers to his questions online. 

cheesescientist.com

The post Can You Eat Mouldy Cheese? appeared first on Cheese Scientist.

SEE ALSO: Jonah’s 10 Commandments for the righteous turophile →

Discoloured patterns on cheese

You’ve seen this pattern of cheese before right? Light is bad for cheese for so many reasons. But, what actually is light oxidation of cheese?

Let’s dive straight into the nerdy science stuff. First and foremost, oxidation of cheese is the process by which oxygen from air attacks fat molecules, proteins and vitamins. Effectively, this sets in motion a chain reaction which can do a fair bit of damage.

This process is also known as lipid oxidation or photo oxidation.

What is light oxidation?

Light oxidation is a very specific type of oxidation that is facilitated by exposure to light (natural and artificial). 

In simple terms, leaving a piece of cheese in direct sunlight or unshielded from bright LED lights inside a cheese cabinet is going to do some bad things to the cheese. Let’s have a look at some of those defects.

The result of light oxidation

The most visible effect of light on cheese is discolouration. This happens because a compound called beta-carotene is broken down during oxidation.

Beta-carotene is present in high levels in cow’s milk and is responsible for the yellow colour we associate with most cheeses.

The loss of beta-carotene means that the exposed part of the cheese will lose its yellow colour and look much whiter. Have a play with the slider above to see what difference light can make.

The impact of light oxidation on taste

Next: flavour. Oxidation produces a large number of smaller molecules which can lead to off-flavours that we often describe as “plasticky” or “cardboardy”.

Remember those Kraft Singles that you ate when you were younger? Their “plastic” flavour actually owes more to light oxidation than the actual sheets of plastic they are wrapped in. And this is from the light inside your fridge!

And the smell

Last but not least, the smell! Most cheeses contain an amino acid called Methionine. And what do you get when you oxidise methionine?

A compound called dimethyl disulphide which most of you will know as the smell of boiled cabbage or potatoes. Not really a desirable trait in cheese, is it?

Protect your cheese from light

To sum up, protecting cheese from light is critical at every stage of the cheese’s life cycle, from production to consumer via the retailer.

I’ve seen so many large cheese displays in supermarkets and so-called specialty cheese shops that have portions of cheese wrapped in clear plastic and exposed to aggressive LED lighting.

Overall, this does a cruel injustice to cheese that has been loving made and matured by an artisan.

Pat Polowski: Gone too soon…

I want to wrap up with a big shout out to industry legend, Pat Polowski.

For those of you who are not familiar with Pat’s work, he was the founder of Cheese Science Toolkit. Through this amazing resource, he shared his incredible knowledge of cheese with all of us.

Pat, you were an inspiration for so much of what I do, including this article on the light oxidation of cheese. You will be sorely missed.

Jonah Kincaid

Cheese lover. Scientist. Created a website and a Youtube channel about cheese science because he could not find answers to his questions online. 

cheesescientist.com

The post What Is Light Oxidation of Cheese? appeared first on Cheese Scientist.