It looks like something chewed through your brie. Or maybe a drill bit slipped during production. You might suspect a defect. You wouldn’t be wrong to look closely. But the truth is far more mundane. And fascinating.
Those holes aren’t damage. They are gas. Specifically, carbon dioxide.
The Science Behind the Holes
When cheese undergoes fermentation, bacteria go to work. They eat lactose. Their byproduct is carbon dioxide. You recognize this gas from sparkling water. In a glass, the bubbles escape. The liquid stays flat eventually. In cheese, the structure is solid. The gas has nowhere to go.
The bubbles get trapped. They expand. They push against the curd. Over time, this creates the characteristic eyes of Swiss-style cheeses. It is a physical trapping of fermentation gas. Simple physics. Biological chemistry.
The holes in cheese are simply carbon dioxide bubbles trapped during fermentation, unable to escape the solid structure.
Not all cheese gets holes. It depends on the bacteria used. Some strains produce gas. Others do not. Cheddar? No holes. Mozzarella? Smooth. Swiss? Classic eyes. The process is deliberate. Cheesemakers control the temperature. They control the aging. They want those specific pockets of air.
Why Summer Cheese Is Darker
You might notice something else. The color shifts. Watch your cheese board. In winter, the wheels often look pale. White. Creamy. In summer? They turn yellow. Deep yellow. Almost orange.
This isn’t dye. It’s grass.
Cows eat what is available. In winter, they eat stored hay. Silage. Dry feed. It lacks pigment. In summer, cows graze on fresh pastures. The grass is lush. Green. And it contains carotenoids. Specifically beta-carotene.
Carotenoids are fat-soluble. They pass into the milk. They do not disappear during processing. They stain the fat globules. The result is a richer hue. Fresh grass equals yellow cheese. It is nature’s coloring agent.
Does Color Mean Quality?
People often assume darker cheese tastes stronger. It doesn’t necessarily. The color comes from diet. The flavor comes from aging, bacteria, and moisture content. A white cheese can be aged for years. It can be sharp. Complex. Pungent. A yellow cheese can be mild. Young. Fresh.
Don’t judge the wheel by its skin. Or its rind. Look at the texture. Look at the aroma. The color is just a map of what the cow ate that summer.
The Takeaway
Cheese is alive. Even when it sits on your plate. It is the end product of microbial activity. And seasonal farming practices. The holes are gas. The color is grass.
Next time you bite into a piece of Emmental or Gouda, remember the cow. And the bacteria. They did the heavy lifting. You just get to eat the result.
