Chris Pearce
Hawai‘i Herald Columist

Imagine yourself a brewmaster at a sake brewery in central Japan. Tottori Prefecture, let’s say, or perhaps Gunma. You’re checking the condition of the fermentation in the tanks when you suddenly get the shock of your life. Instead of the rambunctious, frothy activity you expect as carbon oxide pushes up through the dissolving rice nutrients to produce a heady foam, there is . . . nothing. Bubbles of escaping gas rise to the surface, and there’s a quiescent layer of foam, but for all intents and purposes, it just looks dead to you. The sake has been contaminated by outside bacteria! The fermentation is not happening! This tank is going to have to be quarantined and destroyed before it affects the rest of the year’s production!

That’s pretty much how brewers viewed awanashi kobo, or non-foaming yeast, when it made an appearance, which, thanks to its extreme rarity, was hardly at all. At a time when there was no refrigeration, when there were no certified yeasts, when scientific brewing practices were not widely applied, there were many ways that sake could go bad. A simple lapse in hygiene — or a brewery worker bringing a natto musubi to work — could result in an infestation of lactic-acid producing hiochi bacteria that could put a brewery out of business. Or, when you put your freshly bottled sake into a hot water bath to pasteurize it, what if the temperature isn’t right? Spoilage is a real possibility. For the brewers of old, and well into the postwar years, brewing sake was fraught with peril. That scary, apparently non-fermenting sake with no froth — get it out of here!

And yet, for scientists in Japan, the mysterious non-foaming yeast exerted an attraction.

Dr. Hiroichi Akiyama, whose book, “Sake,” was published in English translation in 2010 and contains many interesting facts not available from other sources, headed the research. Kozo Ouchi, a co-author of some of Akiyama’s published papers, laid out the background for this effort in “A History of Non-Foaming Yeasts,” which appeared in the April 2010 edition of the Journal of the Brewing Society of Japan.

His account states that in 1916, Genjiro Takahashi of the Hiroshima Tax Office identified a non-foaming yeast and was able to isolate it and then brew a small experimental tank of sake. However, there was no effort to apply this knowledge to commercial brewing. Sporadic appearances of non-foaming yeast were reported over the years, including one in Niigata in 1931, but were regarded as no more than curiosities.

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