Tobiko, or flying fish roe, is sushi’s version of caviar: Small, salty, and usually orange, it goes on top of many rolls for color and crunch. Unlike most sushi menu items, however, it’s not exactly fresh from the sea. Tobiko is actually a processed food, not unlike maraschino cherries.

Tobiko, which comes from the South Pacific, is a hardy little egg. Unlike other, more fragile and expensive caviar, such as that from sturgeon, it doesn’t need to be separated by hand from the membrane that covers the eggs. Instead, it can be processed in a centrifuge (a machine with a central spinning tub similar to a washing machine, which splits the skeins and lets the eggs float free). The tobiko is then flooded with water to remove foreign objects. It survives being frozen and thawed multiple times without breaking, and still remains crunchy. It’s frozen before being sent for processing, then thawed and processed, then frozen again and sent to purveyors.

In its natural state, the roe has very little flavor and is a pale yellow color. Processing factories add orange or red coloring, along with preservatives such as sorbic and benzoic acid, and flavorings like salt, wasabi, ginger, chili, and squid ink. The final product is then refrozen and shipped to restaurants in plastic tubs.

Even tubbed tobiko, however, is fancier than what some restaurants pass off as flying fish roe. In fact, they’re often using masago—capelin roe—harvested in Denmark and Iceland, and a good deal cheaper. Masago, too, is put through a centrifuge, then exported in a frozen block to manufacturers, who add such substances as salt, food coloring, mirin (a sweet Japanese rice wine), sorbitol (a sweetener), sugar, MSG, soy sauce, and corn syrup.

Photographs by Jen Siska.