SAN JOSE, Calif. — Chester Nozaki said he learned to make tofu through trial and error.

“More so error,” he joked, on a recent Friday morning at San Jose Tofu Company, the shop he runs with his wife Amy.

Chester Nozaki has been working in this tiny storefront since he was 9 years old. His father, Ken, ran it before him. Nozaki’s grandfather, Yoshizo, learned to make tofu while incarcerated at Tule Lake during World War II, and took over the shop from its previous owner soon after the war. Now, at age 61, Nozaki is planning to close up shop for the final time on Dec. 30. The Nozakis have two grown children, but neither plan to take over the business.

I don’t know where my grandfather came up with the idea to open up a tofu shop but we lasted this long.

“We’re just tired, physically, mentally tired of doing this,” Nozaki said, as he grabbed a block of tofu out of a basin of water. “Kind of got tired of listening to customer’s vacations, and I just keep envisioning where I’d like to go someday.”

Since word got out that the 70-plus-year institution in San Jose’s Japantown will be shutting its doors for good, customers have been lining up even more than usual, Nozaki said. Some, like San Jose resident Mas Sato, have been coming here for decades.

“My parents used to buy it back in the ‘50s and ‘60s,” said Sato, who was raised in Japantown. “I’ve enjoyed seeing my parents buy the tofu very carefully and serve it, maybe with some curry or furikake. It was very special.”

Chester Nozaki banters with a customer at San Jose Tofu Company. Grace Hwang Lynch / NBC News

Curt Fukuda, a co-author of “San Jose Japantown: A Journey,” a book about the neighborhood published by the Japanese American Museum of San Jose, said that the Nozakis’ tofu shop is one of the gems of the neighborhood. “The business produced handmade soy bean cakes that many people regarded as superior to what you could find in Japan,” Fukuda said.

The Nozakis and a third employee make the tofu by hand each day, starting at 2 a.m. Dried soy beans are soaked and then squeezed to make fresh soymilk, which is mixed with “nigari” — a coagulant derived from sea water — and ladled into wooden molds.

On the morning of the recent Friday when NBC News visited, Amy lifted the cover off a tray, peeled back a layer of cheesecloth, and pressed a finger on the quivering mass. “Too soft,” she decided, and set the cover on for another ten minutes.

“Once, my dad let me make a few batches myself. It looked really good until someone would take the tofu out of the water, and it just fell apart,” Chester Nozaki, who was nicknamed “Tofu Boy” growing up, recalled. “Once it was on the tray the customers were just looking at this blob. They would walk out and tell other customers, ‘Be careful. The son made the tofu today.’”

Chester and Amy Nozaki making tofu at San Jose Tofu Company. The couple plan to close the business by the end of the year. Grace Hwang Lynch / NBC News

Over the years, the Nozakis have perfected their technique. When it is time to release the finished tofu from the molds, the husband and wife each grab a side of the wooden tray and carefully lower it into a vat of water, where it is unmolded and cut into squares. The Nozakis’ tofu is known for its creamy consistency and pure flavor.

“The milk is more fresh, the tofu is more softer. The tofu with sugar is delicious. It is amazing,” Mai Nguyen, a customer waiting in line, said. A refugee, Nguyen has come to San Jose Tofu Company since she arrived in the U.S. after the Vietnam War.

“I come here in 1975, and I stop by from that time until this time,” she said, noting that the familiar flavor of fresh bean curd was a comfort to the many refugees who relocated in the city.

I’ve enjoyed seeing my parents buy the tofu very carefully and serve it, maybe with some curry or furikake. It was very special.

While some customers are Japanese Americans whose parents and grandparents remember when Nozaki's grandfather ran San Jose Tofu Company, the clientele has now very diversified. Amy, who is from Taiwan, greets some regulars in Mandarin.

Even though this neighborhood just north of downtown San Jose is one of the U.S.'s few remaining Japantowns — home to a large Buddhist church, a Japanese-American museum, and many restaurants and boutiques — the neighborhood also has a long multicultural history, Fukuda, the author, noted.

“While the Japanese-American presence might not be as strong as 50 years ago, San Jose Japantown has always been pan-Asian. It was never only Japanese,” he said. “The Chinese established the neighborhood first and then, the Japanese and the Filipinos added to the community. Today, other Asian cultures are adding to the mix of Japantown.”

During these last few weeks, the Nozakis have been selling out of tofu around midday. With each batch producing only 42 squares of bean curd, they only make between 200 and 300 pieces per day. Most of it is sold directly to customers and some to a handful of neighboring restaurants. Cooks often walk in with buckets to pick up their daily supply.

“Yesterday I came in at 2 o’clock and they were sold out at noon,” Barbara Williams-Sheng, who has been a customer since 1982, said, noting that she had brought her own boxes. “So I left my containers here," she added. "Amy said she would fill them to make sure I would get my tofu today.”

We’re just tired, physically, mentally tired of doing this. Kind of got tired of listening to customer’s vacations, and I just keep envisioning where I’d like to go someday.

Others customers have heard about the shop’s closing and wanted to get a taste of the famous tofu — and Nozaki’s sense of humor.

“What kind of tofu do you have?” one woman asked.

“Porterhouse, Rib Eye, Top Sirloin…” Nozaki deadpanned.

After they close their doors, the Nozakis hope to visit some of the places their customers often talk about, such as Hawaii, Japan, and Taiwan. While the couple are not interested in selling their business or recipe, Amy Nozaki said they may consider re-opening in some other — less back-breaking — form after some rest and vacation.

“I don’t know where my grandfather came up with the idea to open up a tofu shop but we lasted this long,” Chester Nozaki said.

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