At the heart of brewing sake is koji, a mold

Don't call sake a rice wine. According to Gordon Heady, a sake brewer based in Japan and Portland, Oregon, "It's even more complicated than wine." He explains what sake is, how it's brewed and what to look for in stores.

[Pictured above: Heady's colleague, Watanabe-san, steams rice for use in amazake.]

'Sake is sake'

Noelle Carter: I've heard sake referred to as a rice wine, but it's not really. What is it?

Gordon Heady Photo: Amanda Mathson

Gordon Heady: Technically, it's its own category. We don't call a pinot noir a grape beer, and we don't call hefeweizen a wheat wine. Beer is beer, wine is wine, sake is sake.

It's a fermented beverage made from rice, water, yeast and koji. Occasionally there is the addition of a neutral distilled spirit, ethanol, that's often used to either fortify the sake or, ideally, to bring out more flavor and aroma especially.

NC: How did you come to be so passionate about sake?

GH: It started in college. I was tutoring Japanese students who were studying abroad in the States. One of them gave me a bottle of sake in exchange for some extra lessons. That really kicked off my great passion for sake. Even in college, when I wasn't drinking the good stuff, I was enjoying sake just because it's so delicious to me.

NC: Could you describe a little bit about the flavor? What does sake taste like?

GH: It's such an elusive taste. It can have an interesting aroma if you enjoy it in a wine glass, like a Bordeaux-style glass or a Burgundy glass. The chimney effect of the glass can help bring up the aroma.

You're tasting and smelling a wide variety of fruits, whether it's a citrus fruit or a tree fruit; sometimes there's banana that's available. There are certainly spices like anise, fennel or sometimes jasmine. There's a wide variety of flavor and aroma in sake. Because there are 24,000 sakes that are brewed in Japan, you can imagine how many different types of experiences people have with it.

NC: So it's kind of like a wine: There's really no one way to describe wine because there are so many different flavors.

GH: It's even more complicated than wine. If you look at sake chemically, there are two distinguishing factors that make it different than wine. One is aromatic esters that result through fermentation. They've identified potentially 200 esters that could be found in wine. Sake has 400 of these aromatic esters.

Then, amino acids are what I think is really the key to why sake is so delicious. There are 20 amino acids in sake -- more than anything that can be fermented. Wine has 14 of these amino acids.

Glutamic acid is the most important, not only for flavor such as umami, but also for our health. It's said that glutamic acid is the amino acid most found in brain tissue, heart tissue, even mother's milk. Because there's so much glutamic acid in sake, it's delicious. It's difficult to describe what umami is; it's savory or delicious. We find it in cheese, heirloom tomatoes and mushrooms. But we know it when we see it. It's a balanced, delicious taste that feels refreshing and we want more.

Rice, water, yeast and koji

NC: Could you talk a little bit about the sake brewing process?

GH: It's brewed much like a beer, but it's served much like a wine, due to the fact that it can ferment to as high as 20 percent alcohol by volume. I mentioned briefly the four main ingredients of sake: rice, water, yeast and koji.

I work at Wakatakeya Shuzo in Fukuoka, Japan. The brewery has been passed from father to son for 15 generations since 1699. I'm an apprentice to the master brewer. I still have a lot to learn, but I can at least give you an overview.

We take sake rice into the brewery. There's actually a local co-op that polishes the rice. The reason we polish brown rice to make it smaller is that there are what are considered impurities on the outside of the rice that prevent us from brewing a really delicious sake. Those impurities are good for our health, but they're not good for fermentation.

We polish rice when it comes into the brewery. We would do it inside of a two-story mill that works a little bit like a rock tumbler. After anywhere from 15 hours to, in some breweries, up to 72 hours, the rice has become smaller. The smaller the rice is, the more premium it's seen in the marketplace. On average, 30 percent of the rice is removed, but on the super premium sakes it's 40 percent, 50 percent or even 60 percent or more.

At this point we have this polished rice; it looks like little pearls in your hand. We wash and steep the rice. We steam it. After we've steamed the rice, we begin the koji-making process. Not to get into too much of the details, but koji is really the heart of sake brewing. Koji is a mold, Aspergillus oryzae, that's propagated around and into steamed rice over a 2-day period. It's the heart of sake brewing.

Heady works in the koji-muro, the climate-controlled room where steamed rice is transformed into koji through the successful propagation of Aspergillus oryzae over a 2-day period. This is the most critical time in the successful brewing of sake. Photo: John Esslinger

At this point, we're ready to start the shubo, or the seed mash. We take this koji, which was once steamed rice that has the mold growing around it, and we take yeast and water and we start a seed mash and we get a ferment going. Then from that ferment, we'll take it into the ginjo-ba [the room where premium sake ferments], the moromi room. The moromi is a main mash. Then we'll make three additions, each one larger than the other -- it's called sandan-shikomi.

After the fermentation cycle is done, we press sake. We take sake that's cloudy and turn it clear. There's filtration involved. Now we have this clean sake and it's ready for pasteurization, packaging or aging. Typically sake is aged 6 months, but it can be consumed very fresh. That style of sake is called shinshu; it's one of my favorite styles to drink.

What to look for when buying sake

NC: What should Americans look for when they're buying sake?

GH: In a restaurant, stay away from the warm or the hot sake and ask for premium sake from Japan. There's a style of sake called ginjo, which is a ratio of the rice polish that I was referencing earlier. Ginjo sake is a premium sake that I like to recommend.

Finally, if you're in a supermarket, try to be careful about what you're buying. Sake doesn't cellar the way the wine does. Try to find sake that's been bottled or produced within the last year or so. Because sake suffers from light strike, look for sake that comes in a dark bottle, or sometimes you'll see it wrapped in newspaper or gauze. These are things that I like to tell Americans to look for if they're unfamiliar with brands. But in the end, experimentation will yield great results.