The cheese manufactured and sold by the Swiss company Emmi owes its distinctive flavor and texture to a technique that is 22 million years in the making. In addition to milk, bacteria cultures, rennet, and other ingredients, Emmi cheese makes use of ancient sandstone caves in the Santenberg mountain.

Whatever you might expect upon entering the Kaltbach Cave, nothing can quite prepare you for the way it has been developed into a vital element of cheesemaking. The 1.4 miles of corridors are home to 156,000 aging wheels of cheese. Naturally maintained at temperatures between 50-53 degrees Fahrenheit and humidity levels of 96%, the cave provides the ideal conditions for aging Emmi cheese, contributing to its unique qualities.

Most of the cheeses in the cave are Emmentaler and Gruyère. They age in the cave for at least nine months. Every 7-10 days, each cheese wheel is inspected, turned, washed, and brushed with brine solution. The specifics of this practice, known as cheese refinement, are handed down through a carefully-guarded process of apprenticeship, where secrecy is maintained by keeping the instruction verbal and not running the risk that any written instructions be carelessly passed along to a competitor.

Emmi has been using the cave since 1993. Connoisseurs of cheese have come to appreciate how the mineral deposits on the sandstone the cave’s climate contribute to the distinctive flavor, aroma, and texture of Emmi cheese. The cave’s qualities are also responsible for the signature dark brown color of the cheese rinds.

See this infographic about the cheesemaking process of Emmi cheese.

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