Blue Cheese vs. Moldy Cheese

Cheese enthusiasts have likely heard the age-old debate - is the mold in blue cheese something to savor or a sign of spoilage?

Blue Cheese vs. Moldy Cheese

While blue cheese intentionally contains certain edible molds, finding fuzzy mold growth on other cheese varieties sparks the question of whether it's still safe to eat.

What Are Cheese and Mold

Cheese is a beloved fermented food with origins stretching back thousands of years. Early cheesemakers soon realized that leaving milk to curdle and age developed complex flavors and textures. While this was originally an accidental discovery, today's cheesemakers scientifically harness microbes for desirable results.

Mold is a type of fungus that grows filament-like branching structures called hyphae. The fuzzy splotches we associate with mold are actually masses of hyphae called mycelia. Mold spores are ever-present in our environment, though most only grow in the right conditions of warmth, moisture, pH, and nutrients.

Fermentation relies on microbial activity to transform foods. So in a sense, much of the unique taste, aroma, and mouthfeel of aged cheeses is thanks to forms of fungus like mold and yeasts. However, not all molds are created equal - some provide distinctive character, while others lead to spoilage.

Delicious Molds: Varieties Used in Cheesemaking

Certain strains of edible mold are purposefully harnessed in the production of many classic cheeses. Let's look at some of the most popular varieties:

Penicillium Roqueforti

This species is used to produce blue cheeses like Roquefort, Gorgonzola, Stilton, and Danish blue. It imparts signature blue-green veins and a pungent, salty flavor.

Cheesemakers inoculate the milk or curds with P. roqueforti before aging the cheese in temperature and humidity controlled environments. This allows the mold to flourish and generate enzymes that break down proteins and fats, producing a soft creamy texture and characteristic taste.

Penicillium Glaucum

A close relative of P. roqueforti, P. glaucum is used to make other blue cheeses like Gorgonzola. It grows best at cooler 60-70°F temperatures and produces blue-gray veins.

Penicillium Camemberti

This white mold is used to make soft-ripened bloomy rind cheeses like Brie and Camemberti. It grows as a thick, velvety white rind which contributes an earthy, mushroomy flavor.

The rind also affects the silky, oozy interior by raising the pH and encouraging other microbes to further ripen the cheese. While visually striking, P. camemberti rinds are typically not eaten.

Brevibacterium Linens

This reddish-orange bacteria is commonly found on the rinds of stinky washed-rind cheeses like Muenster, Limburger, and Stinking Bishop. It produces distinct aromas associated with smelly feet or body odor through compounds like isovaleric acid.

Mucor Species

These grayish mold fungi are used to make Camemberti and soft-ripened cheeses in conjunction with white P. camemberti molds. They help soften the rind and modify the pH to achieve characteristic gooey textures.

In short, whether a mold is delicious or deleterious depends entirely on the strain and cheesemaking context. While these molds may seem unappetizing when described on paper, they interact with the cheese curds during aging to generate tantalizing textures and tastes that cheese lovers crave.

Key Takeaway: Well-known edible molds used in cheesemaking include Penicillium roqueforti for blue cheese, Penicillium camemberti for bloomy rinds, and Brevibacterium linens which produces stinky aromas.

Undesirable Molds: Signs of Cheese Spoilage

We established that certain molds are used to make tasty cheeses like Roquefort and Brie. However, mold growth can also indicate spoiled cheese past its prime. Some signs of unfavorable fungal growth include:

  • Fuzzy spots in hues of green, gray, black, or white
  • Dry, crumbly areas that are inconsistent with the cheese type
  • Pungent, sour, or bitter aromas
  • Change in texture from smooth and creamy to slimy or gritty
  • Visible mold penetration deep into the interior of the cheese
  • Presence of air pockets or hollow voids

The reasons cheeses grow undesirable molds depends on several factors:

  • Storage conditions like temperature, light exposure, and humidity
  • Age and whether it's passed the used-by date
  • Insufficient drying during the cheesemaking process
  • Contaminated equipment or facilities
  • Cutting cheese with shared utensils that spread mold
  • Bacteria and yeasts that modify the pH and moisture to help molds thrive

The fuzzy spots we commonly perceive as mold are the fruiting bodies that generate spores for reproduction. Though these growths start small, they can spread rapidly to colonize an entire block of cheese if left unattended.

Consuming cheese contaminated with hazardous molds puts you at risk for adverse health effects:

  • Gastrointestinal distress like nausea, vomiting, and diarrhea
  • Respiratory irritation or difficulty breathing when mold spores are inhaled
  • Allergic reactions including sinus issues or skin rashes
  • Antibiotic resistance to penicillin-based drugs
  • Toxin exposure from mycotoxins that have immunosuppressant, neurotoxic, or carcinogenic effects

Clearly, it's ill-advised to eat spoiled moldy cheese that could introduce such harmful microorganisms into your body. But are there exceptions? Let's explore proper protocol when you discover moldy cheese in your fridge.

To Cut or Discard: Dealing with Moldy Cheese

You return home with an eager craving for charcuterie and cheese. But when you flip on the fridge light, your savory plans turn scary. That pricey aged gouda you've been saving is now adorned with fuzzy green polka dots. Quelle horreur! What should you do?

Here are some guidelines for dealing with moldy cheese:

Soft Fresh Cheeses

Discard at the first sign of mold. Their high moisture content allows mold to spread rapidly. This includes:

  • Ricotta, cottage cheese, and chèvre
  • Cream cheese, mascarpone, and burrata
  • Mozzarella, paneer, queso fresco
  • Fresh soft goat cheeses like Montrachet

Semi-Soft Cheeses

Evaluate mold severity. Trim off any superficial growths and consume the rest immediately. But discard if mold penetrates deeply ortexture changes. Types include:

  • Havarti, fontina, Monterey jack, muenster
  • Asiago, gouda, Edam, Gruyere
  • Some bloomy and washed rind cheeses like Camemberti, Reblochon, Taleggio

Firm/Hard Cheeses

Cut away mold at least 1 inch around and below the growth. Rewrap and consume the remaining intact portions. Note color changes under the mold. Good candidates:

  • Cheddar, Colby, Swiss
  • Parmesan, Asiago, Romano, grana padano
  • Gouda, Gruyere, Emmental
  • Pecorino, manchego

Blue Cheeses

Discard if you see off-colored mold or fuzz not part of the blue veining. For example, fuzzy white or gray spots indicate spoilage. Safe options:

  • Roquefort, Stilton, Gorgonzola
  • Danish blue, Cambozola
  • Buttermilk blue

Bloomy Rind Cheeses

Remove moldy rind and consume the interior if the texture remains intact. Discardif the paste is excessively runny or separating. Includes:

  • Brie, Camemberti
  • Brillat Savarin, explorateur
  • Saint André, pierre robert

Washed Rind Cheeses

Cut away discolored or fuzzy mold and eat the remaining cheese. Examples:

  • Taleggio, Morbier
  • Chaumes, Limburger
  • Époisses de Bourgogne, Langres
  • Munster, Pont l'Évêque

What About Mold Powder?

Some people recommend cutting off mold and then treating the remaining cheese with a vinegar or lemon juice wash or scraping the cut surface with vitamin C powder. This supposedly destroys mold roots and spores.

However, there is no scientific evidence that DIY washes effectively remove mold from cheese. Play it safe by trimming visibly moldy areas and closely inspecting cheese interiors before consuming.

Knowing these best practices empowers you to salvage accidentally neglected cheeses. However, remember that mold development indicates temperature regulation issues or ignoring use-by dates. Follow smart storage rules to get the most out of your precious fromage.

Key Takeaway: Soft fresh cheeses should be fully discarded if moldy. For hard cheeses, trim 1 inch around and below any mold. With bloomy rind and washed rind cheeses, simply remove affected areas.

Storing Cheese Correctly to Prevent Unwanted Mold

Cheese requires specialized storage conditions to prevent spoilage. Here are some cheese care tips:

  • Keep refrigerated at 35-40°F in the cheese drawer
  • Ensure low humidity - wrap cut surfaces in parchment or wax paper
  • Allow airflow and don't use plastic wrap long-term
  • Separate cheese varieties and foods in container partitions
  • Clean utensils after each use and avoid cross-contamination
  • Label with purchase dates and follow use-by recommendations
  • Inspect frequently and discard moldy portions promptly
  • Freeze very hard cheeses like parmesan if you won't finish quickly
  • When freezing cheese, allow it to thaw in the refrigerator to prevent moisture damage

Following these rules keeps your cheese fresher for longer. And learning to identify good versus harmful molds means you can confidently enjoy cheese moments after they peak in flavor.

Blue Cheese: Embracing Mold for Deliciousness

We've covered how to recognize and handle moldy cheese. Now let's appreciate the world of mold-ripened cheeses and what makes them special.

Blue cheese is the poster child for edible mold in dairy products. Within the expansive category of blue cheese exist many delightful varieties, each with their own distinctive characteristics imparted by carefully cultivated Penicillium:


  • Made from raw sheep's milk in the Roquefort-sur-Soulzon region of France
  • Aged in natural Combalou caves growing native P. roqueforti mold
  • Crumbly texture and robust flavor with spicy, salty tang
  • Prominent in salad dressings and dips or eaten with fruits and nuts


  • Originates from three English counties - Derbyshire, Leicestershire, and Nottinghamshire
  • Uses pasteurized cow's milk inoculated with P. roqueforti
  • Semi-soft and buttery with bold earthy and nutty notes
  • Often enjoyed with pears, apples, or port wine


  • Created in the town of Gorgonzola, Italy from cow's milk
  • Aged using P. glaucum to form blue-green marbling
  • Smooth, creamy varieties like Gorgonzola dolce and firmer, crumbly versions like Gorgonzola naturale
  • Pairs well with balsamic, honey, raisins, and prosciutto


  • Danish semi-soft cow's milk blue made by Danisco
  • Subtler blue flavor more approachable for beginners
  • Melting properties make it excellent on burgers or sandwiches
  • Commonly used in blue cheese buffalo wing sauce

This demonstrates the impressive diversity within blue cheeses based on milk type, aging duration, mold strain, and regional traditions. Beyond blues, bloomy rinds, washed rinds, and cheese surface molds also deliver trademark tastes warranting celebration.


How can you tell if blue cheese has gone bad?

Look for off-colors like gray, beige or pink instead of blue. Avoid blue cheese with brown, yellow, or black mold spots. Ammonia-like odors also indicate spoilage.

Is it safe to remove mold from cheese and eat the rest?

It depends on the cheese variety. With hard cheeses, trim 1-inch around/below mold. Soft fresh cheeses should be discarded entirely. When in doubt, play it safe and toss it out.

Why does mold grow quickly on some cheeses but rarely on aged hard cheeses?

Moisture content affects mold growth. Soft fresh cheeses have high moisture allowing rapid mold growth. Hard aged cheeses are low moisture so mold rarely penetrates below the surface.

Can you get sick from eating cheese with mold on it?

Yes, cheeses with unintentional mold can cause illness through bacteria, allergenic spores, or toxins. Health risks include digestive issues, respiratory distress, and antibiotic resistance.

What makes blue cheese mold safe to eat vs. other molds?

Blue cheese uses edible Penicillium strains that don't produce harmful mycotoxins. Other molds like black, yellow, or fuzzy white molds may contain toxigenic species or unpredictable pathogens.


All cheese requires meticulous mold management - whether that's blocking undesirable fungi or purposefully cultivating agents of deliciousness.

While mold can indicate spoiled dairy, when selectively harnessed it transforms fresh curds into transcendent aged cheese.

Cheese Lover Chloe 🧀
Cheese Lover Chloe 🧀

I'm a total cheese fanatic! When I'm not busy studying to be a cheesemaker, you can find me scouring local farmers markets and specialty shops for new and exciting cheeses to try. Brie is my all-time fave, but I also love exploring aged goudas, funky blues, and rich creamy camemberts. Looking forward to sharing lots of melty, gooey cheese pics and reviews!