Why is brown rice sushi so awful? Here's the science

Meat was seldom on the menu when I was a kid. When we did eat it, my family's go-tos consisted of hot dogs (consumed once per year at my dad's work picnic), kung pao chicken from various local Chinese establishments, and my mom's tandoori chicken slathered in yogurt sauce. These dishes all followed my formerly vegetarian, reluctantly omnivorous Hindu parents' Cardinal Rule for Eating Meat: Meat should not resemble animal. Skin and bones were to be avoided, which meant that chicken wings and ribs were inherently problematic, as were Thanksgiving turkeys, which were replaced with lasagnas.

Sushi was never on the radar (fish as a whole was out, given its fishy qualities), but it ostensibly fit the Cardinal Rule, given that the fish was skinless and boneless. And best of all, it was covered in rice, the best food known to (Indian) man (and woman). I tried sushi for the first time in the summer of 2001 in an upstate New York college town to prepare for my forthcoming teaching stint in Japan. (Since I'd gone completely vegetarian in high school, it was also the first piece of animal flesh I had eaten in seven years). To be honest, I don't remember the taste of the sushi as much as the experience, which, as the years have passed, has lodged in the part of my brain reserved for nostalgia.

Sometime upon my return stateside two years later, an abomination began to appear on the menus of local sushi joints: brown rice rolls. The holy triad of salt, sugar, and vinegar had gone out of whack; the rice grains tasted like grit.

So I was shocked (shocked!) when a friend of mine told me that he liked brown rice sushi. An Indian, fellow rice-loving friend. A friend who should know better. Was it really possible, I began to wonder, to make brown rice sushi taste as good as its white rice counterpart?

Early iterations of sushi might have been made with brown rice, says Mori Onodera, former chef and owner of Michelin-starred restaurant Mori Sushi in Los Angeles and current co-owner of Tamaki Farms, Inc., a rice farm in Uruguay. But in modern times, making the perfect sushi roll means balancing the flavors and textures of the rice on the outside and the fish, vegetable, or egg on the inside. Brown rice, says Onodera, upsets that delicate balance.

The first problem is flavor, a word that generally evokes happy thoughts. But in the case of sushi, the earthy, fiber and nutrient-rich bran and germ in brown rice tend to overpower the delicate fish inside.

The second problem is texture. Rice (which comes in 40,000 varieties) contains two starches, amylose and amylopectin, the ratio of which determines the rice's texture after boiling. Long-grain varieties like jasmine and basmati are high in amylose and remain firm, while the short-grain varieties used for sushi are high in amylopectin and become soft. Because of its lower amylopectin content, boiled brown rice remains firm.

"Brown and long-grain rice are a disaster for sushi," says Ole Mouritsen, a biophysicist at the University of Southern Denmark and co-author of the forthcoming book Mouthfeel. They have the "completely wrong texture and mouthfeel."

"Rice and fish are supposed to melt [in your mouth] together," adds Onodera. "If you're using brown rice, the fish is gone and the brown rice is still chew, chew, chew."

So if brown rice sushi rolls violate the rules of gastronomic chemistry, why do people like my friend still like them (and not just choke them down for their whole-grain health benefits)? The answer to that, it seems, depends on whether one thinks sushi has reached a sort of culinary zenith or is still evolving and branching into new "species."

To argue the latter case, consider that those following a macrobiotic diet, a whole grain and plant-heavy diet popularized in Japan a century ago, have long made sushi with brown rice and replaced the vinegar and sugar in white rice sushi with umezu, a pickled plum vinegar, says Sonoko Sakai, a cooking teacher and author of Rice Craft.

More recently, as sushi has immigrated out of Japan, it has taken on such novel forms that "American sushi" restaurants have begun to pop up in Tokyo. Arguably a dynamite roll filled with tempura-fried shrimp and slathered with spicy mayo can stand up to a brown rice exterior.

If cuisines can evolve, so, too, can people. By the end of my two-year stint in Japan, I could (to my parents horror) use chopsticks to pick out the meat of an entire, very bony, very skin-covered, cooked sardine. So it's not impossible that my friend is onto something. Perhaps brown rice sushi is tasty in its own, funky new species sort of way.

But ultimately, it's a debate he can't win, logic be damned. Because for me, eating sushi means returning occasionally to my fuzzy, sake-filled memories of a Japan I once knew, where the fish was tender and the rice was soft.

Sujata Gupta is a freelance science writer based in Burlington, Vt. Her work has appeared online and in print in the New Yorker, BBC, NovaNext, Scientific Americanand others. Follow her on Twitter @sujatagupta

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