Kaltbach Cave

In the undulating, green sprawl of an Alpine Valley, clouds swimming against snow-capped mountains, placid cows grazing on verdant meadows, a cave formed from a prehistoric seabed is carrying a culinary secret so glorious that its legacy traverses the globe: from the bucolic idyll of a Swiss vale a few miles from Lucerne, right to your neighborhood supermarket.

For many shoppers who browse the cheese aisle at their local grocer’s, the little wedges of Emmi Le Gruyère, in their translucent wrappers with the blue company logo and the Swiss cross at the top, are hard to miss. But few buyers know that the cheese is meticulously aged at the Kaltbach Cave, a tunnel-like cave within the Santenberg mountain with climatic conditions that are just right for ripening cheese. The cool subterranean labyrinth of the Kaltbach Cave is the natural incubator for 156,000 wheels of cheese, mostly gruyère and emmentaler.

Stretching over a mile, stacked shelves hold the cheeses at temperatures around 50 degrees Fahrenheit year-round, and the cool waters of the river (Kaltbach means “cold river”) that runs through the cave keep humidity levels at around 96 percent. The cave’s unique climate and the interaction of mineral deposits on the sandstone with the cheese create a distinctive flavor and aroma, and give the rinds their signature dark brown color.

Like artists working on their masterpiece, cavemasters turn, wash, and brush the wheels with a brine solution every 7 to 10 days. The cheeses stay in the cave for at least nine months, diligently monitored until they reach just the right aromatic and textural maturity. The art of caring for and gauging the maturity of cheese is called cheese refinement, and it’s a skill transferred down through generations of cave masters at Kaltbach, with no written record of the training.

The cave was discovered in 1953 as a natural cheese-aging habitat when local cheesemakers ran out of storage space and began keeping them in the Kaltbach. In 1993, Emmi acquired the cave and has been storing and aging their finest cheeses in it since. The contribution of this tranquil cave in a Swiss mountain to the cheese boards of the world should go unnoticed no more.