If you’ve ever wondered what caused the formerly large holes — called eyes — found in Swiss cheese, wonder no more boys and girls.

Agroscope, a Swiss agricultural research center, said the phenomenon — which marks famous Swiss cheeses such as Emmental and Appenzell — was caused by tiny bits of hay present in the milk and not bacteria as previously thought.

As it turns out, the topic was under review since 1917 when American William Clark published a detailed article which named carbon dioxide released by bacteria present in the milk as the culprit.

The group published a study in the online edition of the International Dairy Journal with conclusions about why there’ve been fewer holes in the last 15 years and how to change that.

Where once the Emmental, for example, had too many holes in winter, cheeses made in the last 10-15 years have meanwhile fewer holes. It attributes this decline to a still more efficient milking technology and therefore an ever own milk. Agroscope Artists of researchers have hypothesized that the hay microparticles could be causing the formation of holes in the cheese. To study the development of the opening (number, size and distribution) during the refining lasting 130 days, the researchers Artists Agroscope and Empa have developed a new method to study forming the holes by means of the computed tomography. The results of the test series proved amazing. Even researchers Artists-in remained stunned! In summary, the determination of hay particles, it is possible to practically control the opening of the cheese at will.

Régis Nyffeler, a spokesperson for Agroscope, said in a statement that this means that there are fewer, smaller holes in today’s cheese because of the modernization of the cheese-making process. These days, milking is done with machines that keep out more foreign particles than the traditional squirt-into-a-bucket strategy did.

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