Takao Nihei’s Pioneering Sake Research
Hawai‘i Herald Columist
In the summer of 1956, having overcome an outbreak of bacterial contamination that threatened to bankrupt the Honolulu Sake Brewery, Takao Nihei planned to return to Japan and take up his post at Kyowa Hakko, a leading pharmaceutical company active in amino acid research. He was 31 years old at the time, with a golden future in front of him. He would continue to research and publish, perhaps becoming the laboratory director of a major brewery, or even the director of the National Research Institute of Brewing. For Nihei-san, the temptation to return to Japan and embark on this wonderful and fulfilling life must have been overwhelming.
And yet, after two years of strenuous effort to get Honolulu’s sake up to an acceptable level and then being recalled just months later to deal with a major problem, he knew the situation at the Honolulu Sake Brewery was precarious. There was no reason to believe that sake-making in Hawai‘i — never easy to begin with — could survive without a skilled brewer living in the Islands. Reflecting later on how he came to remain in Hawai‘i, Nihei-san said it was because of the Issei he had met. “They worked so hard in those sugar cane fields, and they had barely enough money for food and clothes, let alone a glass of sake. But when the Honolulu Sake Brewery started up, all over Hawai‘i, people could afford at least a glass on Saturday night. Many people told me that if it hadn’t been for that one glass of sake, when they could relax and remember the dream that had drawn them to Hawai‘i in the first place, they would have given up and gone back to Japan. And that’s why I decided to stay in Hawai‘i and make sake.”
In his first two years in Hawai‘i, Nihei-san had tamed the troublesome California rice and learned to make good sake from it. He had developed a new technique for preventing spoilage, essential for making sake in Hawai‘i and later adopted by breweries all over Japan. Now, with his home in Honolulu, his wife Misayo beside him and a daughter on the way, he approached his next big challenge: complying with the labor laws of the state of Hawai‘i, which stipulated an eight-hour work day.
Sake-making in those days, and in many breweries today, requires work around the clock. When making koji (mold spores), the steamed rice must be turned over every few hours to ensure that the temperature and moisture content are constant throughout. Unless conditions are ideal, the kojikin, or mold spores, that brewers sprinkle over the rice, will not grow vigorously and produce the enzymes necessary to convert the starch in rice into glucose. And, it won’t create other chemical compounds that help the brewing process (and contribute to sake’s distinctive taste). Strong, healthy koji is essential for making good sake.
Nihei-san had determined that he could largely overcome the shortcomings of California rice if he could make really good koji. He had experimented with many different koji mold spores to find the one most suited to the ingredients he had. However, this effort would be useless unless the koji was made properly, and this required stirring it at 11 p.m., 2 a.m. and again at 4 a.m. to keep it within the temperature range needed to convert starch into glucose and then through the action of the yeast into alcohol.
In the 1950s, the Honolulu Sake Brewery made not only sake, but also shöyu, which, similarly, utilizes koji. Shöyu-making isn’t as exacting as sake-brewing, and manufacturers did not make their koji by hand. Instead, there was a machine that aerated the rice that had been inoculated with koji spores and then stirred and rotated it according to a set schedule automatically. As he passed by the shöyu section of the brewery, for which he was also responsible, he came up with the idea of mechanizing sake koji-making along similar lines.
With the help of some Honolulu machinists, Nihei-san was able to build a sake version of this device and found that it worked quite well. In fact, koji made mechanically this way was firm on the outside and not soft — the ideal that brewers strive for because the rhizomes of the koji mold and then penetrate to the heart of the rice kernels rather than just subsisting on the nutrients in the outer layers. Thanks to this technological improvement, Nihei-san was now able to produce as much koji as the brewery needed without enlisting a single worker for nighttime duties. And, the quality of Honolulu Sake Brewing Company’s “Takara Masamune” improved as a result.
Getting rid of the foam was another huge challenge. Fermentation was going on in the brewery constantly, releasing large amounts of carbon dioxide in the process and producing foam that had to be removed to prevent it from overflowing onto the brewery floor. You could lose a lot of sake that way and breweries had workers known as awaban whose duty it was to check the vats at night and keep this from happening. During the most active phase of fermentation, the foam had to be skimmed off once an hour — and not just from one tank, but from several tanks. To solve the labor law problem, Nihei-san had to come up with solutions to both the koji-making and foam challenges — challenges that few, if any, breweries in Japan had successfully met at that time.
The foam was a byproduct of yeast fermentation, a frequent subject of papers in The Journal of the Brewing Society of Japan, which publishes research on sake, beer, and wine and spirits, as well as shöyu, miso, nattö, and other fermented foods and beverages. Oftentimes, an issue will carry an ad that lists the different kinds of sake-brewing yeasts that are available for purchase from the Society. Most brewers in Japan order their yeast here, basing their decision on the preferences of their töji (brewmaster) and what kind of sake they intend to make. A recent edition lists 23 yeasts that can be ordered in either small ampules or larger amounts.
Scrolling down the yeast listings, one thing stands out. Of the 23 yeast varieties available for purchase, 14 are awa-nashi kobo, or non-foaming yeasts. These are essentially identical to their parent yeasts, except that they do not produce a thick layer of foam at the top of the brewing tanks during fermentation. Just one gene in the DNA structure determines which kind of yeast it’s going to be. Historically, sake has only been made from yeasts whose foam takes up about 30 percent of the area in the tanks at the peak of fermentation activity.
By the 1950s, some breweries in Japan had installed automated foam-skimming devices. The Honolulu Sake Brewery had not and had to pay its workers overtime to do this tiring work throughout the night. “This was really a problem,” Nihei-san wrote. “The work week in America was 40 hours. If it went beyond that, a company had to pay time and a half overtime. It’s not like Japan where staff can work at any time of day or night.”
It’s hard for us to imagine now how exciting it must have been for Nihei-san in 1959 when he noticed that the level of foam in one of the fermentation tanks was extremely low — and yet the fermenting moromi (mash) appeared normal. Taking a sample, he placed it under the microscope he kept in a small laboratory next to his office. Under high magnification he was able to isolate a mutant yeast that produced carbon dioxide but very little foam.
Reporting his discovery, he wrote, “It was a complete coincidence, but I noticed that one of the tanks had almost no foam, although it had a good aroma and the fermentation was proceeding vigorously. I thought this was odd, and so I isolated the yeast. Carefully, dreading I might make a mistake, I tried out the mutant yeast at our brewery. And what I found was that it worked especially well with California rice and produced no foam. It was amazing.”
For Nihei-san, this non-foaming yeast was much more than a microbiological curiosity. It signaled a path to overcoming his greatest challenge: how to structure sake-making into the eight-hour day as stipulated in Hawai‘i’s wage and labor laws. This would be a tremendous benefit to the brewery workers since they would no longer have to wake up at night to skim the foam off the top of the fermentation tanks. And for the Sumida family, owners of Honolulu Sake Brewery, it meant they could make up to 30 percent more sake in each tank, greatly improving both efficiency and profitability. Within a few months of this discovery, the Honolulu Sake Brewery became the first in the world to have a 40-hour work week.
Next month: The sake establishment in Japan downplays the discovery of Hawai‘i’s master brewer.
Chris Pearce is a founding member of Hawai‘i’s Kokusai Sake Kai (International Sake Association) and was instrumental in establishing the U.S. National Sake Appraisal. He coordinates the annual “Joy of Sake” events held in Honolulu, Tökyö and in cities on the continental U.S.