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Please help settle a friendly argument about coffee. Does a latte cool faster than a cappuccino, all else being equal (initial temperature, volume, etc.)? My friend thinks the foam on a cappuccino will insulate it better, but I reckon this effect is offset by the cappuccino having a smaller volume of hot milk. (continued)

Paul Whiteley
Bittaford, Devon, UK

This is an ideal question to demonstrate why empiricism beats theoretical musing. The way this query was answered previously (10 December 2022) was in terms of heat absorption, evaporative cooling, conduction coefficients, latent heat etc. (though the answer missed out colour: darker colours radiate heat quicker). All of these parameters require a considerable amount of data and prior research to establish coefficients.

The empirical answer is to stick a thermometer into each cup and measure them.

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