I used to like Japanese food because it was less fattening than other foods I lost weight eating sushi. Now I like it because the Japanese eat so much fermented food: miso, pickles, yogurt, Yakult, umeboshi (pickled plums), natto, vinegar drinks, and alcoholic beverages. A Tokyo food court might have 20 types of pickles, 15 types of miso, and 10 types of umeboshi.
Abundance of fermented food isn’t the only way Japanese food is unusual. I see Japanese food as an outlier on three dimensions:
Use of fish. More fish-centered than any other major cuisine.
Beauty. More beautiful than any other cuisine.
Fermented food. More fermented food than any other cuisine.
As I’ve said , lightning doesn’t strike twice in one place for different reasons. If two rare events could have a common explanation, they probably do. I’ve discussed before why a fish-centered cuisine could lead to better visual design : Because cooks can’t use complex flavorings to show how much they care (it would make all fish taste the same), they take pains with appearance to convey this.
What about fermented foods? Here’s an idea: In the development of Japanese cooking, lack of complex flavoring of main dishes increased desire that other parts of the meal provide complexity, which is what fermented foods do so well. For example, Japanese meals often include pickles. We want a certain amount of complexity in our food, in other words. Most cuisines provide complexity via complex spice mixtures (mole sauce, harissa, curry powder); Japanese cuisine provides it with fermented foods. (I love Japanese curry, but it isn’t common.)
This explanation predicts that desire for complexity is like thirst: It grows over time and can be satisfied. Prediction 1: Eating one complex food will make a second one will taste less pleasant, just as drinking one bottle of water will make a second bottle of water taste less pleasant. Prediction 2: Over time, the pleasure provided by complexity grows. The same complex-flavored food will taste better at Time 2 than Time 1 if you haven’t eaten anything with a complex flavor between the two times.