Holes in cheese have a habit of making people suspicious. They look deliberate. They look engineered. They look like something went wrong and everyone collectively agreed not to talk about it.

And yet, when you slice into a good Havarti and see those small, irregular openings scattered through the paste, you’re not looking at a flaw. You’re looking at a record of microbial activity. A frozen moment of fermentation, captured mid-conversation between bacteria, milk, salt, and time.

Havarti doesn’t have holes because someone poked them in. It has holes because the cheese was alive while it was being made.

Let’s unpack what’s actually going on inside Havarti. And why its holes are smaller, softer, and very different from the famous eyes of Swiss-style cheeses.

First, what kind of cheese is Havarti?

Havarti is a washed-curd, semi-soft cheese, traditionally made from cow’s milk. It originated in Denmark in the 19th century and was designed to be supple, sliceable, and gently aromatic rather than firm or crumbly.

From a structural point of view, Havarti sits in an interesting middle ground.

• It’s not elastic like Mozzarella.
• It’s not dense like Cheddar.
• And it’s not engineered for big, dramatic eyes like Emmental.

That middle position matters. Because holes only appear when a cheese’s internal structure is soft enough to stretch, but firm enough to trap gas.

Havarti is exactly that.

Holes are made by gas, not by air

This is the single most important thing to understand.

Cheese holes are not pockets of trapped air. They are bubbles of gas created inside the cheese after the curd has formed.

That gas comes from bacteria.

During fermentation, certain bacteria metabolise compounds in the cheese and release carbon dioxide as a by-product. If that gas can’t escape, it accumulates. Slowly. Quietly. Pushing against the surrounding protein network.

Eventually, a void forms. That void is a hole.

In Havarti, the process is subtle. The bacteria involved are not aggressive gas producers. The curd is not designed to stretch dramatically. The result is small, irregular openings rather than big round eyes.

The washed-curd step sets the stage

To understand why Havarti gets holes at all, we need to look at how it’s made.

Havarti is a washed-curd cheese. After the curd is cut, some of the whey is drained and replaced with warm water. This step does three important things:

1. It removes lactose from the curd
2. It raises the moisture content
3. It softens the final texture

Less lactose means less fuel for acid-producing bacteria. That’s why Havarti is mild rather than tangy. But the increased moisture also creates a looser protein matrix.

That looser structure matters later.

When gas begins to form during ageing, the paste can deform slightly instead of cracking. It stretches just enough to form small cavities.

If Havarti were drier, the gas would escape or create splits. If it were wetter, the bubbles would collapse.

Holes require balance.

Which bacteria are responsible?

Havarti doesn’t rely on the classic “eye-forming” bacteria used in Swiss-type cheeses. Those cheeses use Propionibacteria, which produce large amounts of carbon dioxide and create big, round eyes.

Havarti uses a more modest microbial cast.

The primary cultures are lactic acid bacteria, which convert lactose into lactic acid early in the make. But during ageing, secondary fermentation can occur. This involves bacteria that metabolise residual compounds such as lactate and citrate.

Some of those metabolic pathways release small amounts of carbon dioxide.

Not enough for dramatic holes. Just enough for gentle openings.

This is why Havarti holes tend to be:

• Small
• Irregular
• Unevenly distributed

They’re not symmetrical. They’re not planned. They’re opportunistic.

Temperature matters more than you think

Holes don’t form instantly. They develop during ageing, and temperature plays a critical role.

If Havarti is aged too cold, bacterial activity slows. Gas production drops. The paste sets before holes can form.

If it’s aged too warm, gas production increases too quickly. The cheese can swell, crack, or develop mechanical openings instead of clean holes.

Traditional Havarti ageing temperatures allow slow fermentation. That gives gas time to accumulate gradually. The curd relaxes. The protein network stretches. Small cavities remain intact.

This slow pace is why Havarti’s holes feel integrated into the cheese, not punched through it.

Why Havarti holes are irregular

Compare Havarti to Emmental and the difference is obvious.

Swiss-style cheeses have:

• Uniform eye size
• Rounded, glossy holes
• Predictable distribution

Havarti does not.

That’s because Havarti’s gas production is inconsistent by design. The bacteria responsible are not specialised gas formers. They produce carbon dioxide as a side effect, not a primary goal.

Gas accumulates wherever the protein network is weakest. That might be near a curd junction. Or around a slightly wetter pocket. Or next to a microfracture from pressing.

Each hole tells a slightly different story.

Pressing plays a quiet role

Havarti is lightly pressed. Enough to knit the curd together, but not enough to expel all internal spaces.

That gentle pressing leaves behind micro-channels and weak points in the structure. These act as starting points for gas accumulation later.

Heavy pressing would close those spaces. No pressing would leave the cheese too fragile.

Again, Havarti sits in the middle.

Are holes a sign of quality?

In Havarti, small holes are normal. They’re expected. They’re part of the style.

That said, more holes is not always better.

Too many holes can indicate:

• Excess gas production
• Poor temperature control
• Imbalanced cultures

Too few holes can suggest:

• Over-pressing
• Over-acidification
• Ageing that’s too cold

Commercial Havarti often aims for a restrained, consistent hole pattern. Artisanal versions may show more variation. Both can be excellent.

The key is integration. The holes should feel like they belong there.

Do flavoured Havarti cheeses still get holes?

Yes. And sometimes more so.

When herbs, spices, or flavour inclusions are added, they disrupt the protein network. Each inclusion creates a local weakness where gas can collect.

This is why dill Havarti, caraway Havarti, or pepper Havarti often show more pronounced openings around the inclusions.

The cheese hasn’t changed its biology. Its structure has.

Why Havarti doesn’t get “eyes” like Swiss cheese

This is a common misconception.

All holes are not created equal.

Swiss-style eyes are the result of intentional propionic fermentation. The cheese is designed to trap large volumes of carbon dioxide. The curd is elastic. The ageing environment is warm. Everything points toward big holes.

Havarti is not built for that.

• Its bacteria produce less gas.
• Its curd is softer, not elastic.
• Its ageing temperatures are lower.

So the gas that does form has nowhere dramatic to go.

It settles. Gently.

Holes and flavour are connected

Those small holes aren’t just visual. They affect flavour.

Holes increase internal surface area. That allows oxygen to interact with the paste in tiny amounts. It also changes how volatile aroma compounds move through the cheese.

This contributes to Havarti’s mild, buttery aroma and soft dairy notes. The cheese breathes, just a little.

It’s subtle. But it matters.

What happens if Havarti has no holes?

It can still be Havarti. Especially in industrial production, where consistency is prized.

But a completely hole-free Havarti often feels denser. Less expressive. Slightly flatter in flavour.

The presence of small openings suggests that fermentation ran its course naturally. That the cheese had time to settle into itself.

Holes aren’t mandatory. But they’re telling.

A quiet record of fermentation

Havarti’s holes aren’t there to impress you.

They’re not a spectacle. They’re not a party trick. They’re a record.

Each one marks a place where bacteria exhaled. Where gas pushed gently against protein. Where the cheese yielded without breaking.

That’s what good cheesemaking looks like. Not control, but guidance.

If you enjoyed this deep dive into the quiet mechanics of cheese, you’ll love my email list. I share new articles, experiments, and behind-the-scenes cheese science straight to your inbox. No spam. Just more reasons to look twice at what’s on your plate.

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 Havarti Has Holes (And Why They’re Not An Accident) appeared first on Cheese Scientist.

If you’ve ever bitten into a young Gouda and thought, “Hang on… is this cheese sweet?” — you’re not imagining things.

Gouda has a reputation for gentle sweetness that sets it apart from many other semi-hard cheeses. It’s not sugary. It’s not dessert-sweet. But there’s a soft, caramel-like note that shows up again and again, especially in younger wheels.

That sweetness isn’t an accident. It’s the result of very specific choices made during cheesemaking, ageing, and even cooking. Gouda is a masterclass in how small technical decisions shape flavour.

Let’s break down why Gouda so often tastes sweet — and why that sweetness changes as the cheese ages.

Sweetness in cheese is not what you think

First, a quick reset.

Cheese doesn’t contain added sugar. And it’s not sweet in the same way fruit or honey is sweet. What we perceive as sweetness in cheese usually comes from one of three things:

• Residual milk sugars
• Sweet-tasting amino acids formed during ageing
• Caramelised or toasted flavour compounds

Gouda just happens to tick all three boxes more reliably than most cheeses.

The washed-curd method: Gouda’s sweetness foundation

If there’s one technical reason Gouda tastes sweet, this is it.

Gouda is made using a washed-curd process. That single choice changes everything.

What does “washing the curd” mean?

After the milk coagulates and the curd is cut, cheesemakers remove some of the whey and replace it with warm water. This step literally washes lactose out of the curd.

Less lactose in the curd means:

• Less fuel for lactic acid bacteria
• Slower acid development
• A higher final pH

And all three push the flavour profile away from acidity and towards sweetness.

Why washing curds reduces acidity

Lactic acid bacteria convert lactose into lactic acid. Remove lactose, and you limit how much acid can form.

That’s why Gouda is:

• Mild
• Creamy
• Rounded
• Never aggressively acid-driven

Compared to cheeses like Cheddar, which retain far more lactose early on, Gouda simply never gets as acidic.

Sweetness isn’t always about adding sugar. Sometimes it’s about not making acid.

Residual lactose and early sweetness

In young Gouda, a small amount of lactose often remains after cheesemaking.

This matters because lactose itself is mildly sweet. Not dessert-sweet, but perceptible when acidity stays low.

Young Gouda can contain:

• Trace lactose
• Low lactic acid
• High moisture

That trio gives fresh Gouda its signature gentle sweetness and milky character.

This is also why young Gouda:

• Melts beautifully
• Tastes creamy rather than savoury
• Feels comforting rather than bold

As the cheese ages, that lactose disappears. But the sweetness doesn’t — it just changes form.

Ageing transforms sweetness, it doesn’t remove it

As Gouda matures, its sweetness evolves.

This is where the chemistry gets especially fun.

Proteolysis: sweetness from amino acids

During ageing, enzymes break milk proteins into peptides and free amino acids. Some of those amino acids taste sweet.

Notably:

• Glycine
• Alanine
• Serine

These compounds don’t scream “sugar”. Instead, they create a soft, brothy, rounded sweetness that sits beneath savoury flavours.

In aged Gouda, sweetness becomes:

• Deeper
• More complex
• Less milky, more caramel-like

This is why older Gouda doesn’t taste sugary, but still feels sweet.

Crystals and concentrated flavour

If you’ve ever noticed crunchy crystals in aged Gouda, those are often tyrosine crystals.

They’re not sweet themselves. But they signal something important.

Crystals form as proteins break down and flavours concentrate. As moisture decreases, everything intensifies — including sweetness.

Less water means:

• Higher flavour density
• Stronger perception of sweet notes
• More contrast between sweet and savoury

That’s why aged Gouda tastes both nutty and sweet at the same time.

Browning reactions unlock caramel notes

Now let’s talk cooking.

Gouda doesn’t just taste sweet when eaten cold. It gets noticeably sweeter when heated.

That’s thanks to browning reactions.

The Maillard reaction in cheese

When Gouda is heated, amino acids and remaining sugars react to form hundreds of new flavour compounds.

These include notes described as:

• Caramel
• Butterscotch
• Toasted milk
• Browned butter

This is why Gouda works so well in:

• Toasties
• Grilled cheese
• Baked dishes

The cheese already leans sweet. Heat simply amplifies what’s there.

Fat carries sweetness more than acidity

Gouda is relatively high in fat. And fat matters for flavour perception.

Fat:

• Softens acid-driven bite
• Extends sweet flavours on the palate
• Enhances caramel and dairy aromas

This is why Gouda’s sweetness feels rounded, not sugary.

Low-fat cheeses can taste sour even with the same acidity, because there’s nothing buffering the acid. Gouda’s fat content acts like a flavour cushion.

Milk choice matters more than you think

Traditional Gouda is made from cow’s milk. And cow’s milk naturally contains lactose and milk sugars that favour sweet flavours.

But beyond species, diet matters.

Grass-fed cows often produce milk with:

• Higher beta-carotene
• Different fatty acid profiles
• Subtler sweetness

That’s why some farmhouse Goudas taste sweeter and more complex than industrial versions, even at the same age.

Same recipe. Different milk. Different sweetness.

Young vs aged Gouda: two kinds of sweet

Let’s zoom out.

Gouda doesn’t have one type of sweetness. It has two.

Young Gouda sweetness

• Comes from residual lactose
• Feels milky and creamy
• Light and comforting
• Almost yoghurt-like

Aged Gouda sweetness

• Comes from amino acids and browning compounds
• Feels caramelised and nutty
• Paired with savoury depth
• Sometimes slightly butterscotch-like

Both are sweet. They’re just speaking different flavour languages.

Why Gouda rarely tastes aggressive

This is worth emphasising.

Gouda’s sweetness stands out because acidity never takes over.

That’s due to:

• Washed curds
• Lower acidity
• Shorter acid development
• Gentle ageing conditions

Even long-aged Gouda avoids the biting acidity you’d expect from similarly aged cheeses.

Instead of sharp, it becomes:

• Nutty
• Brothy
• Caramel-leaning

Sweetness has room to breathe.

Cultural preferences shaped Gouda’s flavour

Cheese styles don’t evolve in a vacuum.

Historically, Dutch cheesemaking favoured cheeses that:

• Stored well
• Traveled safely
• Appealed to broad tastes

Mildness and sweetness made Gouda:

• Easy to eat
• Widely adaptable
• Commercially successful

That gentle sweetness isn’t just chemistry. It’s tradition.

Sweet doesn’t mean simple

It’s easy to dismiss sweet-leaning cheeses as boring. Gouda proves that wrong.

Sweetness in Gouda:

• Balances savoury flavours
• Enhances umami
• Makes bitterness disappear

It’s doing quiet but essential work.

That’s why Gouda pairs so effortlessly with:

• Fruit
• Bread
• Beer
• Wine

Sweetness is the glue holding everything together.

So why does Gouda taste sweet?

Let’s wrap it up.

Gouda tastes sweet because:

• Its curds are washed, limiting acidity
• Some lactose remains early on
• Ageing creates sweet-tasting amino acids
• Moisture loss concentrates flavour
• Heat unlocks caramelised notes
• Fat smooths and carries sweetness

It’s not one trick. It’s a system.

Gouda isn’t sweet by accident. It’s sweet by design.

Final bite

Once you understand Gouda’s sweetness, you start tasting it differently.

You notice it more. You recognise when it shifts. You understand why it works.

And suddenly that humble yellow wedge feels a lot more intentional.

Want more cheese science like this?

If you enjoyed this deep dive into Gouda’s flavour chemistry, you’ll love what I share in my email list.

I send out approachable cheese science, flavour breakdowns, and the occasional myth-busting rant — all designed to make you smarter about what’s on your plate.

Join the Cheese Scientist email list and get smarter about cheese, one bite at a time.

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 Gouda Tastes Sweet: The Science Behind Its Flavour appeared first on Cheese Scientist.

SEE ALSO: The most important items you need in your kitchen to make cheese →

What does curd washing mean?

Curd washing is a cheesemaking process that involves rinsing the curds with water during production. It alters the composition of the curds, primarily by reducing lactose, which later affects the cheese’s flavour, texture and moisture level. This method is used to create cheeses with milder, sweeter profiles and softer textures.

It’s important to distinguish curd washing from rind washing, another technique used in cheesemaking. While curd washing happens early in the process and focuses on the cheese’s internal characteristics, rind washing occurs after the cheese has been shaped.

Rind washing involves applying brine, alcohol or other solutions to the cheese’s surface during ageing, which encourages the growth of specific bacteria or moulds. This method influences the cheese’s outer appearance, aroma and flavour, as seen in cheeses like Époisses or Limburger.

Both methods significantly impact the final product, but they serve entirely different purposes in crafting a cheese’s identity.

Why is curd washing used?

To reduce acidity

When lactose (milk sugar) is present in curds, it serves as food for lactic acid bacteria. These bacteria convert lactose into lactic acid during fermentation, which increases the cheese’s acidity. High acidity creates tangy, umami flavours commonly found in cheeses like Cheddar or Parmesan.

In washed-curd cheeses, rinsing the curds with warm water removes some of the lactose. With less sugar available, the bacteria produce less lactic acid, resulting in lower acidity levels. This shift alters the pH balance of the cheese, yielding milder, sweeter flavours. Reduced acidity also plays a role in creating a more neutral flavour profile, as seen in Gouda and Havarti.

To enhance texture

Moreover, curd washing contributes to the smooth, creamy textures found in washed-curd cheeses. High acidity can cause proteins in the curd to tighten and form dense, crumbly textures, which are desirable for certain cheeses but not for others.

By lowering the acidity, curd washing reduces protein contraction. The proteins remain more hydrated, allowing for a softer, more elastic structure. This process also traps more moisture within the curd matrix, adding to the cheese’s creamy mouthfeel.

In Gouda and Fontina, this science-driven texture is one reason why these cheeses melt so beautifully, making them ideal for cooking and pairing.

To adjust moisture content

The introduction of warm water during curd washing increases the moisture level of the cheese. Water replaces whey in the curds, preventing them from becoming too dry during the pressing and ageing stages.

Moisture impacts several aspects of the cheese:

• Texture: Higher moisture contributes to a softer, more pliable cheese.
• Flavour: A higher water content dilutes certain compounds, which can make flavours more subtle and balanced.
• Ageing: Moisture encourages the growth of certain bacteria and enzymes that work over time to develop complex flavours.

In comparison, dry cheeses like Parmesan or Manchego (both are not washed-curd cheeses) have a much lower moisture content, which gives them a firmer texture and concentrated flavour.

To support ageing

Washed-curd cheeses are designed to mature gracefully, and the washing process is essential to this. By reducing lactose and acidity, curd washing creates an environment that favours specific types of microbial activity during ageing.

• Bacterial growth: Beneficial bacteria thrive in lower-acid conditions, contributing to the cheese’s flavour and aroma over time.
• Enzymatic activity: The enzymes present in milk and starter cultures remain more active in a balanced pH environment. These enzymes break down proteins and fats, producing the complex flavours and creamy textures associated with aged cheeses like Gouda and Edam.

Additionally, the reduced acidity inhibits the growth of unwanted microorganisms, which could spoil the cheese or cause off-flavours. This controlled environment makes washed-curd cheeses more predictable and reliable for ageing.

Balancing all factors

Curd washing is a delicate balancing act that combines chemistry, microbiology and artistry. Cheesemakers use their expertise to fine-tune the process based on the desired characteristics of the cheese, ensuring the perfect balance of sweetness, creaminess, and complexity.

Whether it’s the youthful freshness of a young Havarti or the nutty richness of aged Gouda, curd washing is the key to achieving these unique profiles.

How to wash curds: a step-by-step guide

Washing curds requires precision and care. Here’s how it’s typically done:

1. Cut the curd: Once milk has coagulated, cut the curd into small, even pieces. Cutting increases the surface area, allowing whey to drain efficiently.
2. Remove a portion of the whey: Carefully ladle or drain off a portion of the whey, leaving the curds behind. The amount of whey removed depends on the cheese being made.
3. Add warm water: Replace the removed whey with warm water, usually heated to around 50–55°C (122–131°F). The warm water gently heats the curds and reduces their lactose content.
4. Stir the curds: Gently stir the curds in the warm water. This ensures even washing and prevents the curds from clumping together. Stirring time can vary, but it often lasts 10–20 minutes.
5. Monitor the temperature: Maintain a consistent temperature during stirring. The heat encourages the curds to expel more whey and helps achieve the desired texture.
6. Repeat if necessary: Depending on the cheese, the washing process may be repeated to further adjust lactose levels and acidity. For example, Gouda may undergo two or more washes.
7. Drain the curds: Once washing is complete, drain the curds again to remove the water. The curds are now ready for pressing and further processing.

Examples of washed-curd cheeses

Gouda

Gouda, one of the most famous washed-curd cheeses, originates from the Netherlands. Its creamy texture and mild, slightly sweet taste result directly from the curd washing process.

During production, cheesemakers wash the curds with warm water to reduce lactose levels. This careful step gives Gouda its characteristic balance of sweetness and acidity. Young Gouda tastes mild and creamy, while aged Gouda develops rich, nutty flavours that pair beautifully with wine and fruit.

Havarti

Originating from Denmark, Havarti is celebrated for its buttery, slightly tangy flavour and creamy, smooth texture. Cheesemakers use the curd washing technique to create its mild taste and high moisture content.

Havarti is versatile, making it perfect for sandwiches, melting into dishes, or pairing with fruits and nuts. Its texture becomes firmer and flavours sharper when aged.

Other examples of washed-curd cheeses

While Gouda is a standout, other cheeses also rely on curd washing, including:

• Jarlsberg: This Norwegian cheese features a mild, nutty taste and iconic holes. Washing the curds helps reduce acidity, resulting in its signature sweetness and creamy texture.
• Colby: An American classic, Colby is similar to Cheddar but uses curd washing to create a milder, moister and softer cheese. The process reduces acidity, giving Colby its signature mild flavour and springy texture, which make it a favourite for snacking or melting.
• Edam: Another Dutch cheese, slightly firmer than Gouda but with similar sweet notes.
• Fontina: An Italian cheese prized for its excellent melting properties and mild flavour.

Conclusion

Centuries of tradition have made curd washing an essential part of cheesemaking. The process creates cheeses with mild, sweet flavours and luxurious textures, while also giving cheesemakers control over acidity and moisture levels.

Next time you savour a piece of Gouda or Havarti, remember the art and precision behind curd washing. This seemingly simple step transforms milk into some of the world’s most cherished cheeses.

Would you like to learn more about how Gouda is aged or which pairings work best with washed-curd cheeses? Share your thoughts in the comments!

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 Some Cheeses Are Made By Curd Washing (How-To Guide) appeared first on Cheese Scientist.