You can take the sushi chef out of the lab, but you can’t take the lab out of the sushi chef. Though Henderson Mar had left his research position at the University of Washington Medical School 18 years ago, when he decided to expand his multimillion-dollar Banzai Sushi beyond Seattle, he immediately summoned his biochemistry training.

“In science experiments, freezing is a good way of preserving tissues, so I tried it,” says the chatty, youthful Mar, who, like his wife and business partner, Janis, favors Hawaiian print shirts. “The first few attempts were not very good. The rice was coming out dry. So I made a grid of over 700 different possible parameters using 20 different variables, including the salt-sugar content of the rice, the quality of the rice, and the temperature at which the sushi froze. I finally came out with the right combination, which I have been using since.”

His scientific trials took two years to complete. In the 10 years since Banzai Sushi began selling frozen rolls to grocery stores and food-service distributors, they’ve earned a place in Whole Foods markets around the nation, as well as 13 European countries.

Mar, who grew up in a restaurateur family in San Francisco’s Chinatown district, opened a takeout-meal stand in Westlake Center named Entrées in 1991. But when he realized that a contract producer’s sushi was the stand’s biggest seller, he picked up a copy of Heihachiro Tohyama’s Quick & Easy Sushi Cookbook and learned to roll his own.

Mar and his wife soon traded their retail stand for a production facility, trading up as business grew. Two months ago, Banzai Sushi moved into a SoDo warehouse space with a 100-foot-long freezer. Yet all the maki are still formed by hand, using primarily Pacific Northwest seafood—roughly 5,000 pounds a month of it. Up to 20 stainless-steel work stations are occupied every day, staffed by women in lab coats and plastic gloves who form, pat, roll, and wrap the sushi, scooping rice from two rows of industrial cookers.

Not long after the FDA inspected Banzai’s new warehouse, the Mars had another couple of inspectors: rabbis certifying their facility as kosher. There’s an untapped market for kosher frozen sushi on the East Coast, Henderson says, and beyond that, Israel. “I have no idea where this will stop,” he says, laughing. 3623 Sixth Ave. S., 625-1116, www.banzai-sushi.com.