Jonah Lehrer writes an intriguing post about the primacy of tastes.  He argues that the tastes we are wired to detect through our tongue are more strongly conditioned by evolution than tastes which rely more heavily on the olfactory dimension. As a result, foods that stimulate the receptors in our tongue require less elaborate preparations than foods that we appreciate for their aroma.

His leading example is ketchup vs. mustard.

So here’s my theory of why ketchup doesn’t benefit from fancy alternatives, while mustard does. Ketchup is a primal food of the tongue, relying on the essential triumvirate of sweet, sour and umami. As a result, nuance is unnecessary – I don’t want a chipotle ketchup, or a fancy organic version made with maple syrup. I just want the umami sweetness.

Mustards, in contrast, are foods of the nose, which is why we seek out more interesting versions. I like tarragon mustards, and dark beer mustards, and spicy brown mustards, because they give my sandwiches an interesting complexity. They give my nasal receptors something to sense.

This explains why the market shelves are stocked with countless varieties of mustard but all ketchups are basically the same.

Now what about mayonnaise?  Its primary payload is fat (mayonnaise is emulsified vegetable oil.)  We are strongly conditioned to desire fat in our diet and its attraction is just as primitive as the attraction to sugar and salt. And yet mayonnaise undergoes even more transformations than mustard does.

How does this relate to the fact that the desire for fat is not wired through taste buds, but rather through mouthfeel?