How Beverages Cool: Studying Heat Transfer through Concentration, Convection, and Container Material

Abstract

This study investigated how concentration, stirring, container material, sugar content, particle loading and volume affect the cooling of common everyday stables Coffee, tea and oat mix suspensions were used to model fluids. Temperature changes were recorded using an InfiRay thermal camera over 180–420 seconds. Coffee trials showed that increased solute concentration reduced the cooling rate due to higher viscosity, damping natural convection. Stirring accelerated cooling, promoting forced convection and increasing the convective heat transfer coefficient. Tea experiments demonstrated that sugar addition and container material significantly altered cooling behaviour, with insulated metal cups retaining heat most effectively. The milo-oat trials showed that with increasing particle concentration, mixing within the fluid improves, leading to faster cooling. Smaller water volumes also cooled more quickly because they had lower thermal inertia, as well as, a greater surface-area-to-volume ratio. These findings were consistent with Fourier’s Law of Conduction and Newton’s Law of Cooling, demonstrating how these theories apply in practical situations. Furthermore, highlighting practical insights into the design of beverage containers, ready-to-drink formulations and broader applications in thermal management and food engineering. The use of experimental data along with thermal pictures and theory models is a great method for understanding how to control moving heat around hands-on situations efficiently.