Ken Hirata was eating a plate lunch during a visit to O‘ahu from Japan when he had a thought: “I could make shochu in Hawai‘i.” The surprising catalyst? Poi. The sticky, purple Hawaiian staple made from taro led him to think of the sweet potato, a similar crop that grows well in the islands and an essential ingredient for Japanese imo shochu.
After a four-year-long shochu-making apprenticeship in Kagoshima, Japan, Hirata returned to Hawai‘i and launched Hawai‘i Shochu Company in 2013. Since then, he has produced 22 batches of Nami Hana, his signature imo shochu made from local sweet potatoes. The brand name’s kanji characters mean “wave” and “flower,” but for Hirata, other meanings abound: hana, or flower, refers to the koji, the Japanese mold that “blooms” onto the rice, used for making shochu; nami, or wave, refers to the famous surf breaks on O‘ahu’s North Shore, where Hirata now lives and works.
Along a country road surrounded by farmland in Hale‘iwa, visitors can get a behind-the-scenes look into Hirata’s imo shochu-making process. Upon arriving at the property, guests are invited to remove their shoes and enter the production facility, where instead of the sleek, white-tiled walls and stainless steel surfaces found in modern distilleries, they encounter natural elements of wood, clay, and cement—a testament to Hirata’s more traditional approach.
From there, Hirata segues into a primer on shochu, explaining that imo shochu is just one variety of shochu—any ingredient can be fermented and distilled into the spirit, he says, but “in order to be called authentic shochu, koji must be applied.”
To cultivate koji, Hirata engineered his own koji muro, a special room where shochu’s key ingredient is fermented. The 11-by-16 space, wood-paneled from floor to ceiling, features a large table where Hirata places steaming piles of organic heirloom rice grown in California and sprinkles them with koji spores. After mixing everything together by hand, he places the rice into dozens of neatly stacked wooden boxes to incubate. The wood soaks up excess moisture and regulates humidity, the North Shore’s balmy weather providing an ideal environment for koji mold to grow. Ensuring that the room maintains the perfect temperature and humidity level requires weeks of constant attention, which Hirata manages by opening or closing a vent in the ceiling.
Once ready, the koji rice is brought from the koji muro and combined with water and yeast to ferment for about a week in 150-year-old clay pots sunk into the distillery floor. Outside, in his front yard, Hirata steams sweet potatoes in a giant wooden box, then adds them to the koji rice mixture, or mash, where they ferment for just over a week. Once the mash bubbles a vibrant, purplish magenta, it’s ready for distillation.
According to Hirata, a key characteristic of shochu is that it is distilled only one time. “We prepare a long while before distillation,” he says. “After we distill, we don’t do anything. No flavoring, no additives—nothing.”
Unlike most distilleries, which utilize stainless steel tanks, Hirata opts for a traditional Japanese wooden pot. “Not so many people use this one anymore in Japan,” Hirata says. “I think it does something magical.”
Excited by the growing interest in shochu within the islands, Hirata believes that Nami Hana fans are likely drawn to the spirit’s distinctive aroma and flavor. When served neat, with the sweet potato’s subtle earthy sweetness shining through, it’s reminiscent of vodka. Adding an ice cube unleashes more of its floral notes.
Every spring and fall, Hirata pauses his tours to spend about two months in production. Because shochu-making is a laborious endeavor—each batch takes about six months to produce—each Nami Hana bottle is both an exercise in patience and a call to action; fans must place orders fast, as each production run of 200 to 250 bottles quickly sells out.
Hirata’s tour concludes with much-anticipated tastings of a variety of Nami Hana shochu, each batch made with a different variety of sweet potato and koji seeds. Among the samplings are Hirata’s amber-colored, whiskey-style shochu labeled Banzai Strength, which is aged in barrels of Japanese mizunara oak from Hokkaido, and the aptly named Haleiwa Rainbow, a colorful shochu gin that incorporates ogo limu, mango, ti leaf, hibiscus, and pomelo. All of his produce is sourced from local growers. “Without their support,” Hirata says, “we cannot make shochu here in Hawai‘i.”
