Jarlsberg Archives - Cheese Scientist

Why Does Jarlsberg Cheese Have Holes? The Science Behind Those Perfect Eyes

Jonah Kincaid — Sun, 21 Dec 2025 00:44:35 +0000

If you’ve ever cut into a wheel of Jarlsberg and felt quietly pleased by those neat, cartoon-perfect holes, you’re not alone. Cheese with holes just looks clever. It suggests intention. Precision. Confidence. Nobody accidentally makes a cheese that looks like Swiss engineering.

But those holes are not decoration. They’re not punched out. And they’re definitely not there “to make the cheese lighter” (a persistent myth that refuses to die).

They’re the visible fingerprint of microbiology doing exactly what it’s meant to do.

So let’s talk about why Jarlsberg has holes. And why those holes tell a much bigger story about bacteria, fermentation, and one very Norwegian solution to a Swiss problem.

Jarlsberg is a Swiss-style cheese (with a Norwegian twist)

First, a quick bit of context.

Jarlsberg is what cheesemakers call a Swiss-type or Alpine-style cheese. It sits in the same broad family as Emmental and Gruyère. Firm. Elastic. Mildly sweet. Designed to melt beautifully and slice cleanly.

But Jarlsberg isn’t Swiss. It was developed in Norway in the 1950s by dairy scientist Ole Martin Ystgaard at the Agricultural University of Norway. The goal wasn’t romance or tradition. It was functionality.

Norway wanted a cheese that:

Used local milk
Stored well
Appealed to international markets
Had the nutty sweetness people loved in Swiss cheese

And yes, it needed holes. Because at the time, cheese without holes didn’t scream “premium” in export markets.

Those holes weren’t an aesthetic afterthought. They were a biochemical requirement.

Holes are gas bubbles, not empty space

Let’s get the most important point out of the way early:

Cheese holes are pockets of gas.

Specifically, carbon dioxide.

During fermentation, certain bacteria break down lactic acid and release CO₂ as a byproduct. That gas has nowhere to go. The cheese is semi-solid. Elastic. Trapped.

So the gas collects into bubbles.

As the cheese ages, those bubbles grow, merge, and stabilise. When the wheel is finally cut open, the gas escapes, leaving behind smooth, round holes.

No drilling. No moulds. No Swiss elves with tiny spoons.

Just bacteria breathing out.

The star of the show: Propionic acid bacteria

Jarlsberg owes its holes to a group of microbes called Propionibacterium freudenreichii.

These bacteria kick in after the main lactic acid fermentation has already done its job. At this stage, the cheese is pressed, salted, and moved into warm ripening rooms.

Here’s what Propionibacteria do:

They consume lactic acid
They produce propionic acid, acetic acid, and carbon dioxide

That propionic acid is what gives Swiss-style cheeses their sweet, nutty aroma. The CO₂ is what inflates the cheese from the inside.

No Propionibacteria? No gas. And no holes.

This is why holey cheeses are not an accident. They are designed ecosystems.

Why the holes are round (and not weirdly shaped)

Gas in cheese behaves like gas in dough or balloons. It follows the path of least resistance.

Jarlsberg has a supple, elastic paste. As CO₂ accumulates, pressure builds evenly in all directions. That creates spherical holes, because spheres are the most stable shape under pressure.

If the cheese paste is too brittle, the gas escapes through cracks. If it’s too soft, the bubbles collapse.

Jarlsberg sits in that Goldilocks zone where the curd structure stretches without tearing.

That’s why the holes look so polite.

Milk composition matters more than you think

Here’s where things get quietly nerdy.

Jarlsberg’s milk is partially skimmed. That lower fat content creates a firmer protein network. Casein proteins link up more tightly, forming a strong but flexible matrix.

This matters because:

Strong protein networks trap gas better
Even curd structure promotes evenly sized holes
Excess fat would weaken the walls of the bubbles

In other words, milk chemistry determines hole architecture.

Same bacteria. Same process. Different milk. Different hole pattern.

This is why not every Swiss-style cheese looks the same inside.

Temperature controls hole size

If you want to control holes, you control heat.

Jarlsberg wheels are typically aged in warm rooms, often around 20–24°C, during the eye-forming stage. That warmth wakes up Propionibacteria and speeds up gas production.

Warmer aging:

Faster fermentation
Larger holes

Cooler aging:

Slower gas release
Smaller or fewer holes

Too warm, and the cheese can split or form “blind eyes” where gas escapes unpredictably. Too cold, and you get a disappointingly flat interior.

Jarlsberg producers are extremely precise here. Holes sell consistency. Consistency sells trust.

Timing is everything

Holes don’t form immediately.

First, starter cultures convert lactose into lactic acid. This lowers the pH and sets the cheese structure. Only after this stage do Propionibacteria get involved.

If they start too early:

The curd is too soft
Gas escapes
Holes fail to form

If they start too late:

The curd is too rigid
Gas builds pressure
Cracks form instead of eyes

Jarlsberg’s production schedule is calibrated to give Propionibacteria the perfect window to do their thing.

This is microbial choreography.

Why Jarlsberg holes are smaller than Emmental’s

If you’ve ever compared Jarlsberg to Emmental, you’ll notice something subtle.

Jarlsberg holes tend to be:

More numerous
Slightly smaller
More evenly distributed

That’s deliberate.

Jarlsberg uses:

A slightly different bacterial balance
Tighter curd structure
Shorter or more controlled warm aging

The result is a cheese that looks Swiss but behaves more predictably on the slicer.

Which brings us to a very modern reason holes matter.

Holes are a slicing problem

In industrial cheesemaking, holes are not universally loved.

Large holes cause:

Uneven slices
Weak points
Crumbling

Jarlsberg was engineered to strike a compromise. Enough holes to signal “Alpine-style cheese,” but not so many that the cheese falls apart or frustrates consumers.

This is why Jarlsberg performs beautifully in sandwiches and toasties. The holes don’t dominate the structure. They cooperate.

Holes affect flavour, not just appearance

Those holes aren’t inert. They change how flavour develops.

More internal surface area means:

Increased aroma release
Faster perception of sweetness
More oxygen exposure during cutting

That slightly sweet, nutty aroma you smell the moment you slice Jarlsberg?
That’s volatile compounds escaping from those gas pockets.

No holes would mean a flatter sensory experience.

This is also why pre-sliced Jarlsberg can smell stronger than a solid wedge. Every cut releases trapped flavour.

Why some Jarlsberg has fewer holes

If you’ve ever noticed variation from wheel to wheel, you’re not imagining it.

Hole formation can be influenced by:

Seasonal milk changes
Cow diet
Minor temperature fluctuations
Small shifts in bacterial activity

Modern producers aim for consistency, but cheese is still a biological product. Perfection is managed, not guaranteed.

Interestingly, many cheesemakers would prefer slightly fewer holes. Consumers, however, expect them. When Jarlsberg looks “too smooth,” people assume something went wrong.

The holes have become part of the brand promise.

The myth of “holes for air” or “holes for weight”

Two myths worth retiring permanently.

Myth one: Holes let the cheese breathe.
Cheese does not need internal ventilation. The rind handles gas exchange.

Myth two: Holes reduce weight or cost.
Gas pockets don’t meaningfully change yield. In fact, failed eye formation often leads to rejected wheels.

Holes are not a shortcut. They’re a risk.

What happens when holes go wrong

When eye formation fails, cheesemakers see issues like:

Blind cheese (no holes)
Slits and cracks
Irregular, misshapen eyes

These cheeses are often downgraded or diverted into processing. You don’t see them neatly wrapped at the supermarket.

Jarlsberg’s reputation depends on getting this right, every time.

Why not all cheeses want holes

It’s worth saying this plainly.

Most cheeses do not want gas.

Cheddar, Brie, Blue, Feta, Mozzarella. All of these aim to suppress gas production. Holes in those cheeses signal contamination or process failure.

Jarlsberg is the exception because its flavour and identity depend on controlled gas.

In cheesemaking, holes are either a feature or a flaw. There is no neutral.

The quiet brilliance of Jarlsberg

Jarlsberg looks simple. Friendly. Mild. Inoffensive.

But inside that tidy yellow wheel is one of the most carefully managed microbial systems in modern cheesemaking. Those holes are evidence of:

Bacterial precision
Milk chemistry control
Temperature mastery
Decades of refinement

They are not rustic accidents. They are industrial elegance.

So the next time you see those perfect little eyes staring back at you, remember:
That cheese isn’t empty. It’s alive with intent.

And frankly, that’s a pretty good reason to eat it.

And if you enjoy digging into the science behind everyday cheeses like this, make sure you subscribe to the Cheese Scientist email list. It’s where I share deeper dives, fresh research, and the stories hiding inside your fridge—straight to your inbox.

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 Why Does Jarlsberg Cheese Have Holes? The Science Behind Those Perfect Eyes appeared first on Cheese Scientist.

Jarlsberg Cheese Nutrition Facts (Is Jarlsberg Good For You?)

Jonah Kincaid — Thu, 13 Oct 2022 22:50:30 +0000

Welcome to a tantalising exploration of the nutritional wonders hidden within the creamy folds of Jarlsberg cheese. In this blog post, we embark on a voyage to uncover the fascinating nutrition facts of Jarlsberg, a cheese renowned for its exceptional flavour and versatile culinary presence.

What is Jarlsberg?

Jarlsberg cheese, originating in Norway, is a testament to cheese craftsmanship and heritage. Named after the noble title “jarl“, this cheese carries with it the legacy of its roots.

Its organoleptic properties are a sensory delight, with a pale, buttery hue, a smooth texture, and characteristic round holes. The taste journey begins with a subtle, nutty sweetness that transitions into a creamy, slightly tangy finish. Its aroma is inviting, featuring notes of roasted hazelnuts and mild earthiness.

Serving Jarlsberg cheese is an art; it’s best enjoyed at room temperature and paired with fruits, crackers, or freshly baked bread. Whether melted into a comforting sandwich or featured in a culinary masterpiece, Jarlsberg’s versatility and timeless appeal continue to captivate palates worldwide.

Nutrition fact sheet

Nutritional review for Jarlsberg

Eating healthy plays a pivotal role in maintaining overall well-being and preventing chronic diseases. A balanced and nutritious diet provides our bodies with essential vitamins, minerals, and macronutrients, fuelling optimal physical and cognitive function.

With this in mind, let’s have a look at some of the key nutrition facts for Jarlsberg.

Lactose Intolerance

For those grappling with lactose intolerance, the quest for dairy delights that won’t trigger digestive discomfort is a perpetual challenge. Enter Jarlsberg, a savoury solution with its lower lactose content.

The cheesemaking process transforms lactose into lactic acid, rendering Jarlsberg more digestible for many lactose-intolerant individuals. This moderate lactose content often falls within the tolerance range for a substantial portion of those with lactose sensitivity, allowing them to savour this cheese without worry.

Whether you’re creating a cheese platter, a hearty sandwich, or experimenting in the kitchen, Jarlsberg’s gentle impact on digestion opens up a world of culinary possibilities for lactose-intolerant individuals.

While tolerance levels can vary, Jarlsberg stands as a welcoming option that brings the pleasure of dairy back to the table, adding a touch of creamy delight to lactose-free lifestyles.

Find out everything you’ve ever wanted to know about which types of cheeses are lactose free by clicking here.

Fat Content

Jarlsberg, with its 27 grams of fat per 100 grams, offers a fascinating glimpse into the world of dietary fats and their impact on health.

Saturated Fats: Jarlsberg contains some saturated fats, which, when overconsumed, are associated with cardiovascular health concerns. However, these fats are essential for cell structure, energy and the absorption of fat-soluble vitamins.

Unsaturated Fats: The majority of the fat in Jarlsberg is unsaturated, including monounsaturated and polyunsaturated fats. These fats are renowned for their heart-healthy attributes. They help reduce LDL cholesterol levels, lowering the risk of heart disease and supporting various bodily functions.

Omega-3 Fatty Acids: Some Jarlsberg varieties contain omega-3 fatty acids, known for their anti-inflammatory properties and roles in heart and brain health. While not as rich as fatty fish like salmon, Jarlsberg cheese still contributes to overall omega-3 intake.

Jarlsberg cheese’s mix of saturated and unsaturated fats provides an opportunity to enjoy cheese’s richness while reaping the benefits of healthier fats.

Of course, moderation and dietary variety are key for a well-balanced fat intake.

You can learn more about the different types of fat in cheese and which cheeses have the lowest fat content here.

Cholesterol Content

Jarlsberg cheese contains roughly 100 milligrams of cholesterol per 100 grams. While this number may initially raise eyebrows, it’s essential to delve deeper into the intricate relationship between dietary cholesterol and its effects on our health.

To begin, it’s vital to distinguish between dietary cholesterol, such as that found in Jarlsberg cheese, and the cholesterol levels circulating in our blood. Contrary to conventional wisdom, consuming cholesterol-rich foods like Jarlsberg doesn’t universally translate to elevated blood cholesterol levels.

This connection varies significantly among individuals, often influenced by genetic factors and individual physiology. Cholesterol itself is not inherently harmful; it plays pivotal roles in cell structure, hormone production, bile acid synthesis and vitamin D generation.

Moderation and a balanced approach are paramount when incorporating Jarlsberg into your diet. While this cheese offers a delectable taste and valuable nutrients, it should be part of a well-rounded dietary regimen.

Pairing it with nutrient-dense foods like fruits, vegetables, whole grains, and lean proteins helps maintain overall dietary equilibrium.

Protein Content

Beyond its exquisite taste and creamy texture, Jarlsberg cheese boasts a remarkable protein content of 26 grams per 100 grams, making it a noteworthy contributor to your daily protein requirements.

The protein in Jarlsberg cheese is primarily derived from milk, specifically from casein and whey proteins found in dairy. This protein carries significant importance for your overall health.

Moreover, protein plays a pivotal role in various bodily functions, earning its title as the building block of life. Firstly, it aids in muscle development and repair, making it indispensable for athletes and those seeking to maintain muscle mass.

Additionally, protein supports the immune system by contributing to the production of antibodies and immune cells, helping the body fend off illnesses.

Of course, protein isn’t limited to muscles and immunity; it participates in nearly every biological process, from enzyme and hormone production to tissue repair and oxygen transport in the blood.

Moreover, protein’s satiating effect can assist with weight management by reducing the likelihood of overeating and snacking between meals. It also facilitates vital biochemical reactions within cells, serving as enzymes that accelerate essential processes in the body.

Incorporating Jarlsberg into your diet offers a delectable means of harnessing the benefits of high-quality protein. Whether you’re a cheese aficionado or simply seeking a versatile protein source, Jarlsberg adds a delicious and nutritious dimension to your meals.

Want to find out which cheeses have the highest protein content? Click here for our blog post covering cheeses with the highest protein content.

Safety in Pregnancy

During pregnancy, safety is paramount when it comes to dietary choices. Jarlsberg emerges as a safe and delicious option for expectant mothers, thanks to its pasteurisation process and low moisture content.

Pasteurisation eliminates harmful bacteria, ensuring that the cheese is safe to consume during pregnancy. Additionally, the cheese’s low moisture levels make it less conducive to the growth of harmful pathogens, further enhancing its safety profile.

While Jarlsberg cheese is considered safe during pregnancy, moderation remains key. Like any food, excessive consumption should be avoided to prevent excessive weight gain, which can pose health risks during pregnancy.

Incorporating Jarlsberg cheese as part of a diverse and balanced diet allows expectant mothers to enjoy its creamy, nutty flavour while meeting their nutritional needs and ensuring a safe and healthy pregnancy journey.

Of course, if you’re unsure of what you can eat during pregnancy, you should consult your healthcare professional to get a personalised plan. You can read more about which cheeses you can eat when you’re pregnant by clicking here.

Salt Content

Known for its distinct savoury flavour, Jarlsberg contains approximately 429 milligrams of sodium per 100 grams. While sodium is essential for various bodily functions, including fluid balance and nerve function, it’s important to approach its consumption with awareness and moderation.

Sodium sensitivity varies among individuals, making it crucial to consider your own tolerance levels. Some may be more sensitive to sodium intake and should monitor their consumption accordingly.

Additionally, individuals with specific health conditions, like high blood pressure or kidney issues, may need to limit their sodium intake and seek personalised dietary guidance from healthcare professionals or dietitians.

Incorporating Jarlsberg into your diet can be a pleasurable part of a balanced eating plan. To enhance its nutritional value, pair it with nutrient-rich foods like fresh vegetables, whole grains, and lean proteins.

Calcium Content

Finally, Jarlsberg also provides a substantial amount of calcium, with approximately 825 milligrams per 100 grams. Calcium is a cornerstone of bone and dental health, and Jarlsberg’s calcium content makes it a noteworthy addition to your diet.

Calcium’s importance extends beyond bones and teeth; it’s essential for muscle function, nerve signalling and blood clotting. Specific groups, such as growing children, pregnant women and postmenopausal women, often have increased calcium requirements.

Jarlsberg cheese can be a delicious way for these individuals to meet their nutritional needs and strengthen their bones.

Get our complete guide to calcium content in cheese in this post here.

Conclusion

In summary, Jarlsberg offers a blend of delightful flavours and valuable nutrients. While it provides a rich source of fat and cholesterol, it also boasts high protein and calcium content.

Furthermore, its low lactose levels make it suitable for many, but caution is advised for those with lactose intolerance. Pregnant individuals can enjoy this cheese safely, thanks to its pasteurised and low-moisture characteristics. However, the salt content should be managed carefully.

By understanding the nutrition facts of Jarlsberg, you can indulge in its goodness while maintaining a balanced diet that supports your overall health and well-being.

References

Overall nutritional content

The nutritional content of cheese in our table comes from the USDA Food Data Central Repository, the Australian Food Composition Database and cheese manufacturers. We realise that there can be variations between different brands and producers. Hence, the numbers we have used are averages.

Saturated fat, carbohydrate, and cardiovascular disease – Patty W Siri-Tarino, Qi Sun, Frank B Hu and Ronald M Krauss

Effect of cheese consumption on blood lipids: a systematic review and meta-analysis of randomized controlled trials – Janette de Goede, Johanna M Geleijnse, Eric L Ding, Sabita S Soedamah-Muthu

Safety in pregnancy

All the advice relating to what cheeses you can eat during pregnancy in this article is based on the recommendations by health authorities in Australia, the UK and the USA. If you are unsure about what you can or cannot eat, please consult your doctor.

Australia – FSANZ, United Kingdom – NHS and United Sates of America – FDA