Tea is a drink obtained by infusion of specific leaves into water. There are several organoleptic properties associated with the varieties of the tea plant, Camellia sinensis. We all tasted this drink at least once, but a research team discovered some properties that make a cup of tea clear and tasty.
Applying the principles of a branch of physics known as Reology, i.e. the study of the balance achieved by a mixture of matter in different physical states, scientists Caroline Giacomin and Peter Fisher described the phenomenon of cooling a steaming cup of tea.
A visible film is formed on the surface of the liquid between the liquid component of the tea and the air. This very thin layer, when disturbed by shocks or by the possible insertion of the classic spoon, is fragmented, making the surface finely’maculated’.
By assessing the properties of the film, researchers have found that its formation depends on a number of factors, such as the mineral content of water (hardness), acidity, the inclusion of soluti, such as sugar or milk, the concentration of tea itself, and
According to the study’s co-author Giacomin, on the study methodologies “In interfaced rheology, the experiments carried out involve a metal device placed on the surface of the tea” and continuing “The rotation of that device is carefully controlled and the resistance to rotation
In the past it was common belief that the formation of this layer on the surface was due to the waxy coating of the same tea leaves, but a series of studies have denied this hypothesis, on the grounds that it was really caused by its appearance, identifiable in the amount of calcium carbonate
“The tap water in many regions comes from calcareous aquifers, where calcium carbonate is located, a harmless compound that can make water more crisp,” said Giacomin. But, as the scientist points out, regarding the phenomenon in the United States of “softening” water to reduce the accumulation of carbonate in the household hydraulic systems, “if I had to prepare a cup of tea in perfectly pure water, not forms
So, according to researchers, to obtain a cup of tea that does not have a surface layer too visible, you will just have to opt for a water less hard, but not completely free of carbonate (whose decrease in the sea floor is damaging the oceans), so as not to They also suggest adding an acidic substance, such as citrus juice, which will reduce the visibility of the film and give the drink a better taste.
And, if you were passionate about the origin of the drinks we consume daily, do you know what the most loved drink in the world is and how it was born?