Cheese fondue, with the permission of Swiss chocolate, is the icon of the country’s cuisine, and each chef has their own way of preparing it better than anyone else, but now, a team of Swiss scientists has set out to find the mathematical formula to create cheesy perfection.

Led by Pascal Bertsch from ETH Zurich, the team of experts looked at a branch of physics called rheology, which studies the flow of matter, as the endless debate regarding fondue has always been whether the melted cheese is guilty of being too liquidy or too thick.

When Swiss cooks melt the cheese in the fondue, they mix in small amounts of flour or cornstarch to give it thickness, along with white wine and kirsch (cherry brandy) which produces the opposite effect, so the big challenge is always to strike a balance between ingredients.

“When I was training to be a food scientist, I heard a lot of people talking about how to create the best fondue and what ingredients influence its rheology, but there was no literature on the subject”, Bertsch said during the presentation of his study, which can be found on the university’s official website.

Bertsch and his colleagues used an apparatus in their research to precisely measure the behaviour of a metallic ball in a fluid. This is a system that is widely used when researching landslides, but he had the idea to use it in his Food Processing Engineering Laboratory.

The results of the study, which were recently published in the American Chemical Society’s magazine “Omega”, showed that the cheese should be mixed with 3% starch (flour or cornstarch) for the ball to flow better and “prevent the irreversible separation of the fondue”.

With regard to the wine, they used pure alcohol as a substitute in the laboratory. However, the result was somewhat more complicated to translate into cookbooks. It was stipulated that one should avoid reaching a mixture with a pH of 4.7, as this is when the cheese reaches its maximum level of liquidity and is irreparable.

The study recently made the headlines in the Swiss press, although it is not expected to change the way most people cook fondue, as Hervé Dumoulin, the owner of the Geneva restaurant Cave Valaisanne, believes everyone has their own “mathematical formulas”.

“We often wonder what is best, but our chefs have been making it their way for 10 or 20 years: they put a little flour and some garlic in a bowl and then start to pour in wine, and see if it is too solid or more liquid…”, he said to EFE at his restaurant, which is one of the most famous places to try fondue in Geneva.

Dumoulin, the third generation of a restaurant with more than half a century of history in the city, agrees that “cooking is all about mathematics, but more so for patisserie”, and says that “with good ingredients, it’s not difficult to prepare fondue, and the same principle can be applied to Spanish cuisine”.

Fondue was most probably first made by shepherds in the mountainous areas of western Switzerland in the French-speaking cantons of Vaud, Valais and Fribourg, and is usually made with Gruyère cheese, although many people prefer to mix it with another native Swiss cheese, Vacherin, to create the famous half and half version.

Fondue is the perfect dish to share with friends, you dip bread and other foods in the cheese, but you’ve got to be careful to make sure the cheese doesn’t “sink” and fall from the fork.

“It’s a dish with a lot of calories and fat, so maybe it’s more suited to colder weather in winter, but we make it all year round,” says Dumoulin.

Both scientists and cooks join their hands and minds to avoid one of the greatest embarrassments a person can suffer at a table in Switzerland: serving a fondue that is too liquidy, rubbery or severed like mayonnaise.