Number and Size of Swiss Cheese Holes Can Be Programmed

Holes in Swiss cheese finally give up their gaseous secrets

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About two decades ago Swiss geneticists were trying to figure out how a few vital genes exerted master control over the development of fruit flies. In the course of their work, they managed to get a fly to grow numerous eyes all over its body. Sure, the information is crucial for our understanding of how an individual changes from a single fertilized egg into a differentiated organism, but little to no market exists for the disturbing .

This year a different group of Swiss scientists figured out another vexing eye problem: exactly what causes the formation and development of the numerous eyes (what we laypeople call holes) in Emmental (what we laypeople call Swiss) cheese. The information is crucial for our understanding of how to create cheeses with the right number and size of holes. And billions of dollars in revenues are at cheese-stake in quiches, fondues and sandwiches alone.

To give you an idea of the scope of the Emmental effort, it took 13 researchers at three different Swiss facilities—Agroscope's Institute for Food Sciences, Empa's Center for X-ray Analytics and the Lucerne University of Applied Sciences and Arts—to come up with the study, which was published in the with the title “Mechanism and Control of the Eye Formation in Cheese.” The history is a little unclear, but it looks like it took only one guy, the late Tom Nugent, coach at the Virginia Military Institute around 1950, to come up with the mechanism and control of the I-formation in football.

The connection between the two disciplines can be seen in Green Bay, Wis., where Packers fans proudly recognize their state's dairy prowess by wearing large wedges of faux cheese on their heads. Cheddar may outsell Swiss at the grocery store, but the hat cheese, like the head wearing it at the frozen tundra of Lambeau Field, clearly has holes in it.

The journal article points out that “the size of the eyes of first-quality cheese should be between the size of a cherry … and a walnut.” (To use language more familiar to this magazine's readership, that's between the size of a large ureterovesical cyst and an adult's prostate.) But different people prize different eyes. “Italian consumers prefer Emmental cheese with walnut-sized eyes,” the study authors note, “whereas commercial manufacturers of sliced cheeses ask for cheese with smaller eyes and higher eye numbers.” Thus, you want to control the eyes.

Bacteria do most of the work in cheese making. They produce carbon dioxide gas, forcing the expansion of eyes. If you manage to make what is actually called blind Swiss cheese—no eyes at all—the gas buildup causes slits or splits that reduce quality. Besides, Swiss cheese without holes is a semiotic disaster.

But what makes an eye start to form? Cheese whizzes assumed for the past century that some tiny particle acted akin to the seed of a dust mote, around which a drop of rain forms in a vapor-saturated air mass. The Swiss scientists thus thought, Hay! Dairy farms have lots of hay, and hay dust “could act as highly effective eye nuclei.”

They mixed various amounts of hay particles into embryonic Emmentals and found that they could “control the number ... and size of the eyes in cheese in a dose-dependent manner.” The data should open the eyes of cheese makers worldwide, figuratively and possibly literally.

The intrepid investigators also unintentionally solved a problem that's been bothering Swiss cheese fans: over the past few decades the holes have been getting fewer and smaller. Now we can surmise that better hygienic conditions have been limiting contamination by plant particulates. The result has been the counterproductive reduction in the size and frequency of the holes. In other words, when it comes to cheese, there are none so blind as those that will not seed.

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