One of the World's Most Unusual Beers: Sake
In appearance and flavor, sake resembles wine--which is what it's frequently called. It's right there in the first sentence of the Wikipedia entry. "Sake, also referred to as a Japanese rice wine, is made by..." If you stick around for the full paragraph, though, you'll learn what it really is: beer.
Sake is made, like all beers, by fermenting grain, not fruit, as wine is. Sake's inclusion among the pantheon of beers is at best passing (guilty: it gets a small mention in The Beer Bible), and it is routinely overlooked when we talk about the world's great brewing traditions. I was therefore delighted when, late last year, the SakeOne Brewery invited me for a tour and an opportunity for a little remedial education. I had a vague sense of how this liquid came to be, but only just. My trip to Forest Grove clarified a lot of the questions I had and revealed to me one of the most unusual processes in the brewing world. Keep reading and I'll try to pass those revelations along.
Sake goes back in Japan at least 1,300 years, but could be older. As always, beer production was such a lowly art it wasn't deemed worth documenting by many writers. It has enjoyed hundreds of years of slow refinement. By about the time hops were finally getting to Britain, the practice had become well enough established that practitioners were already using pasteurization. Like all brewing of the pre-industrial era, though, brewing was heavily influenced by the dictates of microbiology and limits to volume production. Technological advances led to a 20th-century product that was far more sterile and stable--and, I suspect, quite a bit less varied. Modern production methods are designed to create clean, reproducible flavors, and funkier looks and tastes, including raw sake, unfiltered sake, and sake made with unusual yeasts, are rare.
Nevertheless, the process of making sake has all the same hallmarks of national tradition we see in other great brewing countries. Sake makers have extremely precise, prescriptive processes for brewing their rice beer, some vestiges of which date back centuries, others that have become received wisdom in the age of science. At each step along the way, there's a right way to make sake, and one followed by all the breweries making it.
Polishing the Rice
The first step in the process is illustrative of the modern refinement/old ways dichotomy that characterizes sake. Rice is fermented, but not the whole grain--just the starchy inner core. Thus sake makers "polish" the rice--which is actually the process of grinding away the outer layers. To do this, sake makers send rice across rough stones that sand down the outer layers. The purpose, as my tour guide, Luis Garcia, told me, “to get to the starchy core so we don’t have any of that bran [?] or fatty acids; those make for bitter and unwanted flavors.”
What's left of the grain are translucent pearly nuggets, ground down to the size the maker wishes. The higher the percentage, the better the quality of sake. When discussing the grade of rice, a percentage is given corresponding to the amount ground away. So the lowest grade is anything below 40%, the highest grade is above 70%, and the middle is in between. SakeOne uses rice in the range of 40-60%, which indicates upper-shelf quality.
There are special sake rices, but the actual grade of rice seems entirely beside the point--in Japan, the sake rices have larger grains, which contain more starch. SakeOne uses California Calrose, which is a bog standard eating rice. This struck me as odd, but seems characteristic to the approach. Good sake is an incredibly refined product characterized largely by fermentation characteristics. The rice offers little flavor by intention; after all, they're grinding away everything but the starches.
After the rice is polished, it's cooked. Rather than boiling it, though, SakeOne steams the rice so that when it's done it's as dry as possible. “We need to steam off as much of the water as possible," Garcia told me.
Koji
The next stage is the most interesting. There are no enzymes in rice, so in order for the starches to be converted to fermentable sugars, brewers do something unusual. Rather than mashing, they apply the spores of Aspergillus oryzae--known in Japan as koji. Koji plays an important role in Japanese cuisine, creating the umami flavors in miso and soy sauce. I asked about what it contributed flavor-wise in sake and Garcia wasn't sure. A bit of research reveals that Japanese sake-makers point to the umami flavors koji gives foods and certain mushroomy, savory sakes. Koji, or koji's interaction with yeast, appears to be responsible.
Once the rice has been steamed, workers break it up to make sure there are no clumps, and then they add the koji spores. "Once those are added," Luis said, "we’re going to hand-mix it to make sure we don’t have concentrated pockets of sugar, because we need it all to get converted.” All of this happens in a special room kept at 90° F (32° C) and from 82-84% humidity. These were traditionally made of thick cedar, which has anti-microbial properties and also handles the heat and humidity fluctuations well. SakeOne built their own koji room of cedar, and it has an austere, Zen-like feel about it. Or a sauna, if you prefer.
The starch-conversion process takes 2-4 days, and if brewers need to interrupt the process (on nonworking weekend days, for example), they can just wheel the rice into a cool chamber and "put the koji to sleep." One the koji has worked its magic, the rice becomes rubbery and all those starches have turn into sweet sugars. Luis gave me a few grains to try, and they tasted like very small, unflavored gummi candy.
Fermentation
The next stage is largely familiar. The sweet rice goes into a small fermenter called a moto along with water, a touch of lactic acid, and yeast. (In the old days, they let the lactic acid form naturally over 48 hours by souring before adding the yeast.) At the moment, there are just a few strains of traditional sake yeast, and all makers, including SakeOne, choose from among them. Of course, this is a modern problem; house yeasts used to be abundant. They're all Saccharomyces strains, though of course even those can vary broadly. Fortunately, sake makers have begun to go on a search for new yeasts to help bring some house character to their own products.
Fermentation. Click to enlarge.
The fermenting grain spends four days in the moto and then goes to the main fermenter, where more yeast and water is added. The koji remain active, precipitating a "parallel fermentation." Interestingly, the sake at SakeOne goes through a very long, cold fermentation. It takes anywhere from two and a half to three and a half weeks at 50° F (10° C). This would seem to inhibit the production of flavor and aroma compounds, though you discover when you drink SakeOne that there are tons of esters. Curious. I have no idea whether there is variation in fermentation practices, nor what would happen if they fermented warmer or used a different yeast.
The one major advantage in sake yeast is its remarkable alcohol tolerance. The mixture of rice and water is thick enough that the yeasts can continue to ferment all the way up to 20% ABV. Most sake is fermented to this level, though it is almost always watered back down to anything from 7-16%.
Filtration
In a regular beer, the grain would be separated from the liquid after mashing and well before fermentation. In sake brewing, the separation happens after fermentation. The device they use is basically a mash filter--an accordion-like mesh that traps the solids. The slurry that comes out of the fermenter is "super thick," according to Garcia. The larger solids (kasu) have to go, but the level of final filtration will determine the kind of sake it is. “The idea is that we’re sending that rice porridge mixture here and this is where we’re going to decide how clear or how cloudy we want it.”
One type of sake, called nigori, is left unfiltered. It has a milky look that, upon close inspection, is indeed made up of tiny particulates. Garcia said this was the standard until modern filtration. “They did it by hand then. Sifting, so much sifting. I can only imagine!” It was laborious enough that clear sake was dubbed "emperor's sake" for its rarity. Now it is nigori that is rare.
Conditioning and Packaging
Following filtration, the sake is pasteurized to stop fermentation. This is typical, though not ubiquitous. In Japan, sake conditions for 8-12 months; at SakeOne, they cut that to 4 to 8 months. Historically, Japanese sake was aged on wood (tatu), or more often cedar (sugi). In the 20th century, Japanese sake-makers switched to enameled tanks. When SakeOne began brewing in 1997, they had these sent over. They work well, and produce what Luis says is a "softer" sake. Unfortunately, no one in the US knows how to maintain them, so when they get cracks or microfractures, there's no one to repair them. At SakeOne they have consequently moved to stainless. (For a "crisp" sake, says Garcia.)
The purpose of aging is much as with beer. Age allows the flavors to develop clearer, more articulated flavors. SakeOne does do an unaged sake they serve on draft at the tasting room. Raw sake is sweeter, more acidic, and “hotter.” It's worth tasting it next to aged sake to see how these subtleties play out. They are subtle, though. To consumers used to the phantasmagoric flavors in American IPAs or the difference between intense, jammy California reds and delicate Northwest ones, the spectrum of flavors in sake seem slight indeed.
Blending and dilution happen before bottling. Blending here done for consistency, not to create unique flavors. Sakes are diluted to taste, usually to around 15% at SakeOne. My sense is that this is a judgment call based on how good the sake tastes as it's being diluted. SakeOne bottles and pasteurizes their sake a second time (also common). It is fairly shelf stable, though Garcia said it should be drunk within a year.
Questions
Luis Garcia isn't a brewer, and couldn't answer many of my more speculative questions--and I had many! (I'm not sure traditional brewers would be comfortable answering them, either; they might have considered them them blasphemous or unknowable.) As I was walking through the facility, I wondered whether exotic rice might make a difference. Wild rice? I already mentioned my questions about fermentation. But what about different strains, like Brettanomcyes, or a mixed strain? What is the koji providing to the flavor, and how do strains change that? There's a lot of pasteurization going on--a hundreds-year-old tradition. But what would happen if they didn't pasteurize their sake? The idea of wood-aging would seem obvious to any beer drinker, and I wonder what oxygen would do over the course of eight months, not to mention the wood itself. Lots there to consider, and I wouldn't be shocked if the craft movement eventually begins to encroach on the orderly ways of sake-making.
Types and Flavor Profile
So what does sake taste like? After the tour, we tasted some of SakeOne's products alongside Japanese examples of the same types. I had already worked my way through the SakeOne sakes and was startled by how fruity the were. Fruit aromas just boiled off the glass. (The brewery does do fruit-infused sakes, but they seem beside the point.) Sake has a silky mouthfeel, which gives it a refined quality. It is always served still, like wine. There are certainly vinous notes, but the viscosity and flavor of rice is unique.
It turns out SakeOne's fruitiness is a choice. The Japanese are more comfortable with umami and savory flavors, and their sakes often have these notes. Luis said they were “more savory, more funky, more earthy, mushroomy, nutty, and malty; ours tend to be fruit-forward. I’m almost certain that’s because the American palate is more familiar with wine, as opposed to savory flavors.” I was of course equally attracted to the Japanese flavors, but I admit that mushroom is not a note most Americans crave in an alcohol.
SakeOne is a big maker, producing over 100,000 cases last year, and it's shipped all over America. I'd recommend trying: Momokawa Diamond (15%), made with rice polished to at least 51%. It's got a full mouthfeel, and is just bursting with melony, peachy aromas; Momokawa Pearl (18%), made with 60% rice and unfiltered (nigori)--it may be a trick of the appearance, but it has a distinctly coconut nose and a rich, silky mouthfeel; and G Joy (18%), a genshu (undiluted) sake also made with 60% rice. The G line are their most premium sakes, and they seem to get more delicate and subtle the more premium they are. The extra octane seems to saturate the flavors more, however.
SakeOne has a fantastic tasting room, well worth a visit if you're out in Oregon wine country. They will happily let you try their sakes next to Japanese sakes, and in a short time you can begin to get a sense of this unusual, exotic, and ancient form of beer.