Why does black coffee cool down quickest?

Black coffee does not cool down quickest. In fact, it cools down at the same rate as other liquids of similar density and volume. The widely-held belief that black coffee cools quicker likely arises due to the contrast in temperature between hot coffee and the cooler surrounding environment. The dark colour of black coffee absorbs more light, causing it to feel warmer to our senses compared to lighter-coloured liquids.