An interesting post at Edible Geography on a recent taste-test:
Previous studies have suggested that some metals in solution actually produce a “metallic” taste — a distinct sensation to add to the standard sweet, sour, bitter, salty, and umami descriptors. This is still a controversial idea in the world of sensory science, where umami took nearly a century to gain official recognition, although among water engineers iron and copper are known to affect the taste and consumer acceptability of drinking water.
In any case, Laughlin, Miodownik, et al. wanted to test the taste of solid metals. They speculated that metals such as copper and zinc that were less stable, and thus more likely to acquire electrons, would taste more metallic because their atoms would form a solution in human saliva more readily. Their blindfolded spoon-eaters (with each lick of a spoon, as Miodownik explained to Dunlop, we are not just tasting metal, but actually “consuming ‘perhaps a hundred billion atoms’”) confirmed the scientists’ suspicions, rating the less chemically active gold and chrome spoons as the most pleasant and sweet tasting, and the more reactive copper and zinc as bitter, strong, and metallic tasting.
[. . .]
Using four samples of Tesco extra thick double cream with sugar, lemon juice (sour), lemon pith (bitter), and salt added, four teaspoons of identical weight, electroplated in stainless steel, copper, zinc, and gold, and thirty human guinea-pigs, Laughlin, Miodownik, Charles Spence, and Betina Piqueras-Fiszman concluded that “cutlery coated with different materials really does taste different,” and, what’s more, that these differences are significant enough to “influence the perception of taste and pleasantness of food consumed from them.”
The more metallic tasting copper and zinc spoons enhanced or added bitter qualities to each of the creams, as expected, but — to the scientists’ surprise — they also boosted its dominant taste. In other words, the sweet cream was perceived as being slightly sweeter when eaten from a copper or zinc spoon than a gold or stainless steel spoon, while the salty cream tasted saltier.
