The Paradox of Sour Food
When researchers consider the classic five categories of taste—sweet, salty, sour, bitter, and umami—there’s little disagreement over which of them is the least understood. Creatures crave sweet for sugar and calories. A yen for umami, or savoriness, keeps many animals nourished with protein. Salt’s essential for bodies to stay in fluid balance, and for nerve cells to signal. And a sensitivity to bitterness can come in handy with the whole not-poisoning-yourself thing.
But sour? Sour’s a bizarro cue, a signal reliable neither for toxicity nor for nutrition. Really, it’s just a , the presence of acid—the citric in lemons, the acetic in vinegar, and the like. “We don’t need sour to live,” Ann-Marie Torregrossa, a taste researcher at the University at Buffalo, told me. “It’s a weird sense to need.” It has been so scientifically neglected that Rob Dunn, an ecologist at
