Traditional Swiss fondue is made from a mixture of two types of cheese
"In Switzerland, you would be disgraced if you serve fondue that is too runny, excessively sticky and thick, or even uneven in consistency. Many myths about recipes for the perfect fondue reign in Swiss kitchens, although science has never studied this issue," say scientists from the Institute of Food, Nutrition and Health at the Swiss Federal Institute of Technology in Zurich, ETH Zurich. As reported by Swissinfo.ch, this incredible and regrettable omission has now finally been corrected.
Let us recall that traditional Swiss fondue is made from a mixture of two types of cheese, Gruyère and Vacherin. Cornstarch and white wine are then added to the mixture. Even novice cooks understand that thick fondue results from increasing the proportion of cornstarch, while runny fondue will be achieved by increasing the proportion of wine. But the Swiss researchers wanted to thoroughly study the issue of fondue consistency.
"The fluidity or rheological properties of fondue are crucial for the perception of taste, aroma, and how well the cheese sticks to the bread," notes the study published in the scientific journal of the American Chemical Society (ACS Omega). The Swiss researchers spent weeks in the laboratory making experimental fondue mixtures, experimenting with ingredients and observing the stretchiness and separation process of the melted cheese.
"The degree of stretchiness of liquid cheese is difficult to measure," said lead author Pascal Bertsch. "But a viscometer, an instrument for measuring viscosity, which is assessed by the speed of a ball falling under gravity in a given medium, handled this task well." He and his group concluded that the determining factor for proper fondue is the setting temperature (i.e., the gelation point) or, in other words, the balance of "the sensations of viscosity and fluidity experienced in the mouth."
By adding pure alcohol and acid separately, thereby imitating wine, they also discovered why white wine thins fondue. "Both ingredients reduced viscosity, but before the experiment we actually expected that the acid would lead to the opposite reaction," said P. Bertsch.
So what is the best recipe for making fondue? "I always put a lot of garlic, but I don't think there is a single best recipe for everyone. We just wanted to understand how different ingredients affect its viscosity," says P. Bertsch.
Incidentally, the scientist noted with surprise that the sharp cheese smell in the laboratory turned out to be "not so bad," so much so that one day he even succumbed to the temptation to personally "taste" the experimental samples. "One evening, around eight o'clock, when I was still in the lab, I spotted leftover bread with solidified fondue. Of course, eating anything in a chemistry lab is at least unwise, but the temptation was too strong," the scientist admitted.
When asked what is best to dip into fondue for better thickening on the fork – bread, potatoes, bananas, or perhaps pineapple – P. Bertsch involuntarily exclaimed, "Not pineapple!" explaining, however, that he and his team of scientists did not conduct experiments with such products.
Incidentally, let us recall that in 2010, the University Hospital Zurich (Universitätsspital Zürich) brought much-needed clarity to the fundamental debate about what is gastronomically better for washing down fondue – black tea, white wine, or cherry schnapps.
"When consuming fondue with large doses of alcohol, gastric emptying after Swiss cheese fondue occurs much more slowly, and a decrease in appetite is observed. But when fondue is washed down with tea or water, this process proceeds much faster," stated the conclusion of a study conducted on 20 healthy and hungry volunteers.