Tea Time Gets Flavor Boost from Thin Film, Impure Water

In Physics of Fluids, researchers describe how they applied rheology to the seemingly quaint purpose of improving the quality of a cup of black tea. They describe the interfacial phenomenon in a cup left to cool after steeping, when a thin film at the air-water interface can form, and assess the mechanical properties of the film, the formation of which is affected by water hardness, acidity, sugar or milk, tea concentration, and brewing temperature.

The Problem with Microwaving Tea

Through convection, as the liquid toward the bottom of a container warms up, it becomes less dense and moves to the top, allowing a cooler section of the liquid to contact the heating source. This ultimately results in a uniform temperature throughout the container. Inside a microwave, however, the electric field acting as the heating source exists everywhere and the convection process does not occur. Researchers studied this nonuniform heating behavior and present a solution in AIP Advances.