Why does cheese have holes?
Show answer & explanation
Answer: Bacteria produce carbon dioxide
Bacteria produce carbon dioxide ✓ — Correct! Swiss cheese holes (eyes) form from Propionibacterium freudenreichii bacteria added during cheese-making. These bacteria consume lactic acid and produce carbon dioxide gas. As cheese ages, CO2 bubbles get trapped in the elastic curd, forming holes. More bacteria = more holes. Modern clean milk produces fewer holes (less hay dust for bubbles to nucleate on)!
Mold eats passages through cheese — Wrong. Mold grows on cheese surfaces (like blue cheese veins), but Swiss cheese holes are gas bubbles from bacterial CO2 production.
Cheese shrinks leaving gaps — Wrong. Cheese doesn't shrink enough to create large holes. Holes are CO2 gas pockets from bacterial fermentation.
More Food & Nutrition questions
- Parmigiano Reggiano is made with milk, salt, and rennet only, so why can older pieces taste more savory or spicy without extra seasoning?
- Why does a Parmigiano Reggiano wheel wait until at least 12 months for the official selection mark instead of being fully approved when it is molded?
- How can Parmigiano Reggiano keep developing flavor after its starter bacteria have done their early acid-making job?
- A young Parmigiano Reggiano can taste milky, while older wheels lean nutty, spicy, or broth-like; what pushes the flavor away from plain dairy?
- Why does aging Parmigiano Reggiano from 12 months to 36 months not matter much for removing lactose?
- Why can older Parmigiano Reggiano turn crumblier and grainier instead of simply becoming a harder block?