In my first column of 2011 I write about the blizzard of specialty salts that now come our way from all over the world, and describe two recent academic studies that examine whether different salts actually do have distinctive tastes.
A few additional points for which there wasn't room in the column:
The flavor descriptors compiled by the taste panel include four odors, which are sensed in the nose rather than on the tongue. One of them is "mineral," which the study defines as "aromatic associated with a copper penny or rusty nail." Because wine lovers often associate "mineral" flavors with rocks and rocky soils rather than metals, I avoided the term and instead referred to the odor of penny and nail. I would describe their odors as "metallic," but the salt study used that term for the "feeling factor of metallic (metal spoon)."
And in his classic book on salt and brines, Dale W. Kauffmann gave a plausible explanation for how less refined salts could seem to taste saltier than pure table salts, at least when they're put right in the mouth. He pointed out that trace calcium and magnesium chlorides on the surface of the less refined grains absorb moisture--this is why gray sea salts are clingy rather than free-flowing--and that surface layer delivers its predissolved minerals immediately to the taste buds.
Bitterman, Mark. Salted: A Manifesto on the World's Most Essential Mineral, With Recipes. Berkeley: Ten Speed Press, 2010.
Drake, S.L. and M.A Drake. Comparison of salty taste and time intensity of sea and land salts from around the world. Journal of Sensory Studies, 2010, doi 10.1111/j.1745-459x.2010.00317.x
Kauffmann, Dale W. Sodium Chloride: The Production and Properties of Salt and Brine. New York, the American Chemical Society and Reinhold Publishing, 1960.