Understanding Awa Sake

Understanding Awa Sake

Sake, the rice-based alcoholic beverage, is deeply rooted in Japanese culture. It is believed that sake was first produced during the Yayoi period, which spanned from roughly the fifth century BCE to the third century CE—around the same time as rice cultivation. The beverage is as intrinsically tied to Japanese cuisine as it is to rice itself. Today, quality is at a premium, but sake is falling out of favor with younger generations in the country, forcing breweries to find innovations that speak to not only domestic drinkers but the ever-important international markets. Traditional method sparkling, known as awa (meaning “foam”) sake, is one such invention.

The History of Sparkling Sake

Sparkling sake is not a new concept, but, until recently, the only style on the market was force-carbonated, slightly sweet, unfiltered nigori sake. Low in alcohol and high in sugar, it was the ubiquitous choice for a sparkling option.

About 15 years ago, a couple of brewers experimented with a second fermentation in bottle. One of them was Hideyuki Takizawa, the president and sixth-generation owner of Takizawa Shuzo, in Saitama Prefecture. After working as a moromi analyst for a Tokyo brewery, Takizawa returned to his family’s business in 2008 and started trials on traditional method nigori sake, but he had issues with stabilizing pressure, leading to exploding bottles.

For Takizawa and other brewers, traditional method sparkling sake remained mostly a side project until 2013, when the International Olympic Committee announced Tokyo as the location for the 2020 Summer Olympic Games. The excitement around the global competition became the impetus for brewers to create a celebratory, toast-worthy sake. Breweries such as Hakkaisan, in Niigata Prefecture, refocused efforts on crafting clear sakes using the Champagne method. In 2016, the Japan Awasake Association, comprising nine members, was formed to create standards around awa sake production, educate interested brewers, and market this new category of sake. Today, the association has 33 members.

Awa Sake Regulations

The Japan Awasake Association is overseen by a board of directors from member breweries, who work together to create quality standards through a certification process. They also educate members through seminars and trainings on all aspects of the business, from brewing to marketing.

For a sake to receive the awa sake designation, several criteria must be met:

  • Sake must be made only from Japanese rice, koji, and water.
  • The addition of alcohol is not allowed; only Junmai styles are permitted.
  • CO2 must come from a natural second fermentation. Forced carbonation is not allowed.
  • The finished product must be transparent.
  • A stream of bubbles must appear in the sake.
  • The sake must be at least 10% ABV.
  • The sake must be at least 3.5 bars of pressure at 20 degrees Celsius (68 degrees Fahrenheit).
  • Aromas and flavors must remain stable for three months at room temperature. Pasteurization is encouraged.

Twice-yearly inspections of each awa sake brewer’s facility and equipment, as well as audits by a third-party institution, are conducted to ensure all standards are met.

Production Methods

Still sake is produced via a multiple parallel fermentation process, where starch breaks down into sugar while, simultaneously, sugars are being fermented into alcohol. Only five elements are needed for sake production: rice, water, koji (a type of mold), yeast, and lactic acid.

After harvest, rice is polished, washed, soaked, steamed, and cooled. It’s then portioned out for various production purposes. Some of the rice is sprinkled with koji, and the mold propagates over a 48-hour period. This koji rice is combined with steamed rice, water, a yeast culture, and lactic acid (producers may add a commercial strain, or they may allow lactic acid to develop through the naturally occurring process of either kimoto or yamahai). This yields the yeast starter, called shubo, or moto. Once the shubo is developed, steamed rice, koji rice, and water are added to form the moromi, an active fermentation mash. Over four days, more steamed rice, koji rice, and water are added incrementally. This is followed by two weeks of multiple parallel fermentation. Once fermentation is completed, brewers may opt to add distilled alcohol (resulting in a Honjozo style) or not (resulting in a Junmai style). The moromi is pressed to separate the sake from the lees. The liquid is racked, filtered, and pasteurized before being transferred to tanks. Right before bottling, sakes from different tanks are blended, and water might be added to balance alcohol levels. The sake is pasteurized again and, finally, bottled.

Base sake for awa sake production is brewed identically to still Junmai sake, then bottled. Unlike in Champagne, sugar addition is not allowed, so the most common method for activating a second fermentation is incorporating moromi into the dry bottled sake. Brewers have their own methods for this process. Some, such as Hakkaisan, add moromi as a winemaker would add liqueur de tirage to still wine. Kosuke Kuji, a fifth-generation brewer and the president of Nanbu Bijin, in Iwate Prefecture, brews and presses—but does not filter—the sake, which leaves a bit of moromi mash in the liquid. He then gradually raises the temperature over six weeks, and the residual moromi kick-starts the second fermentation. One could equate this to the ancestral method. Takizawa prefers to bottle a cuvée composed of 95% dry sake and 5% roughly filtered sake. The small percentage of enzymes in the blend is enough to start a secondary fermentation with a gradual temperature increase.

Once the second fermentation is completed, bottles go through a riddling process, either by hand or by machine. Sake spends almost no time on its lees, however, as most is meant to be consumed in a bright and fresh style, and lees aging does not provide the characteristics brewers seek in awa sake.

After disgorgement, the sake is topped off with liquid from a sacrificial bottle. Again, as sugar addition is not allowed, there is no equivalent of dosage in awa sake production—essentially, all awa sake is brut nature. Timothy Sullivan, the global brand ambassador for Hakkaisan, explains that any desired sweetness must be determined in the fermentation stages, when the koji breaks down the rice starch into glucose. By controlling residual sugar levels, brewers can adjust sweetness in the final sake’s profile.

To finish, the beverage is pasteurized and bottled under cork.

The Elements of Sake

In still sake production, rice varieties, yeast, and water—and, to a lesser extent, koji strains—factor into the final style of the sake, much like grapes and terroir form the backbone of winemaking. As awa sake is still a relatively new category, brewers are deep in the research and experimentation phase, examining how the fundamentals of sake translate in a carbonated beverage.

Rice

Yamada Nishiki is the most common rice variety used for sake production, but, as the broader sake industry continues to evolve, research is being conducted into different rice varieties, with an emphasis on cultivating and working with local varieties from various prefectures. Awa sake brewers currently use whatever rice is used for their still sake production, as perfecting the brewing process is a higher priority than rice selection.

Understanding how seimaibuai (the percentage of a remaining rice grain after polishing) affects awa sake production and styles is also in its nascent stages. Kuji trialed rice polished to 70%, 55%, and 40%. At 40%, which is used for the premium Daiginjo class of dry sake, he found the aromas were somewhat muted and the sake came across as too clean. At 70%, the style he was seeking wasn’t achieved, so 55% became his ideal polishing ratio, resulting in both the finesse and the juiciness he wanted in the sake. 

Yeast

Brewers purchase yeast, which is closely associated with the aromatic profile of sake, from the National Research Institute of Brewing. Spontaneous fermentation is seldom heard of in the sake brewing process for fear of volatile microorganisms spoiling the shubo. Experiments into different strains for awa sake production remain sporadic.

Takizawa Shuzo, however, produces a rosé sake using a red yeast. As a weak fermentation starter, this saturated strain requires high temperatures to activate and impart color. It’s also a sensitive strain and easily loses its color if it touches other yeasts, so Takizawa produces only small batches at the end of the brewing season to avoid cross contamination. 

Koji

Koji, one of the most distinct ingredients in sake production, is a fungus that provides the enzymes needed to break down rice starch into glucose and supply the vitamins and amino acids needed for yeast propagation. Yellow koji is most often used in sake production, but, depending on how breweries start a second fermentation, a different strain of yellow koji may be used for awa sake. For example, Nanbu Bijin’s still sakes contain only 1–2% glucose, but, for awa sake, to give the yeast enough sugar to kick-start the second fermentation, a koji that produces more glucose is required. The brewery found that 5% residual glucose is ideal.

Some breweries are experimenting with white koji, used in the production of shochu, which yields a higher citric acid level, but these awa sakes have yet to be exported.

Water

Sake is 80% water. This natural element has an outsize effect on style and quality. Historically, good water sources determined where sake industries would flourish. Potassium, phosphoric acid, and magnesium are vital minerals for propagating yeast and developing rice koji. For awa sake, these minerals also provide enough fodder for the yeast to complete a second fermentation. In terms of character, Kuji says that minerals give a “spine” and structure to awa sake, an otherwise soft and low-acid beverage.

An Overview of Styles

Unlike Champagne, awa sake, like sake in general, is low in acid. It also has fewer bars of pressure than most sparkling wines, resulting in a mousse-like texture on the palate. Tira Johnson, the wine director at ILIS, in Brooklyn, New York, says that styles can range from crisp and linear, much like a brut nature sparkling wine, to softer and plusher.

In general, just as nonvintage Champagne conveys a house’s distinct profile, an awa sake reflects the signature style of the shuzo (brewery). Takizawa wants his awa sake to mirror the taste of moromi, which for him translates to a tingling sweetness on the tongue. Hakkaisan aims for aromas of melon and a clean, dry finish, while Kuji, of Nanbu Bijin, says, “Our sake flavor is between brut and non-brut: juicy, silky, kind of melty, like biting into ripe fruit.” Dewatsuru offers a nice creaminess on the palate, while Dewazakura Sake Brewery produces a dry and crisp style.

How to Serve Awa Sake

Johnson serves awa sake by both the glass and the bottle at ILIS, which bills itself as a wood-fired kitchen that highlights ingredients from North America. She also always incorporates it into the restaurant’s 12-course tasting menu.

Johnson explains, “Sake is a lot more delicate and doesn’t have as much acidity as wine, so it’s a fun beverage to pair with dishes that are delicately flavored,” such as fish crudo. Because sake is high in amino acids, it also works with foods such as eel. “Sake picks up the nuances of the umami,” she says. Likewise, Sullivan, of Hakkaisan, thinks awa sake works well with cheese because of the strong umami components of both. But the fruit profiles found in many awa sakes make them extremely versatile. Johnson says that awa sake works equally well with a dessert course; fruit-based desserts, such as pavlova, are a particularly good match. 

When serving sake by the glass, Johnson likes to use half bottles. She says that once sparkling sake is opened, its bubbles tend to dissipate quicker than those of sparkling wine, so smaller vessels are ideal for managing waste.

For pairings, there’s a psychological factor associated with serving awa sake. Johnson says that pouring these sakes, especially with a tasting menu, sets expectations for the dining experience: awa sake signals that people are about to go on an adventure. As a newer beverage on the market, it also provides great talking points with guests. For the uninitiated sake drinker, it’s easy to draw parallels between awa sake and a more familiar beverage, such as Champagne. 

Johnson notes that many non-Japanese restaurants bring Japanese cooking techniques and influences into their cuisine, so sake should have a foothold in a beverage list as well, and offering guests more beverage options beyond beer and wine always leaves a positive impression.

At l’abeille, a one-Michelin-starred French Japanese restaurant in Manhattan, David Bérubé, the group beverage director, often incorporates awa sake into the tasting menu and also offers it by the glass and the bottle. He says that, when introducing a new beverage category to guests, it’s best to keep the explanation simple, so he talks about how production of awa sake is the same as that of Champagne. But to further intrigue diners, he tells them that it’s a rising category in the beverage world, and one to keep an eye on.

Bérubé’s advice to others when presenting awa sake to guests is to express that it’s a style of beverage with its own strict quality regulations. He says, “For me, the fact [that] the best breweries, the ones I like to talk about and serve, are making awa sake is a sign that it’s a style that is being taken very seriously.” He wants guests to understand that it’s not a side project or an experiment. “It’s its own category, with its own rules.”

Pairing-wise, Bérubé finds the texture to be a refreshing counterpoint to creamy risottos or pastas. Awa sake also works as a twist on the classic combination of fried foods and Champagne. When served with tempura, he says, “It has the same palate-cleansing impact as Champagne.”

He advises avoiding pairing awa sake with high-acid dishes and with red meat, which is too rich and powerful for a harmonious pairing.

Looking Ahead

The US remains a vital market for Japanese breweries. In 2021–2022, it ranked first in the total volume of exports (102.9% increase) and second in the total value of exports (114% increase), according to the Japan Sake and Shochu Makers Association. While numbers aren’t available for awa sake specifically, the overall trend is promising for this new category.

Takizawa is such a believer in the product that he wants to grow awa sake to account for half of his total production, up from its current level of 10%, and Nanbu Bijin wants to increase its awa sake production fivefold.

More experiments with yeast, rice, and koji are also important for brewers. How awa sake ages will be another point of development; Kuji has a small library of back vintages that he plans to release in the coming years.

Sullivan explains, “The reason that I think awa sake is such a key product for all of these breweries in the association is that they view it as a bridge product.” Looking at its traditional cage and Champagne cork, consumers understand how to handle and open the bottle, that they should use the same glasses they would for other sparkling wines, and what temperature would be optimal for serving. Sullivan says, “It is a format that wine lovers know, appreciate, and understand. It reduces a lot of the barriers for wine lovers to explore sake.” 

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Bibliography 

Inoue, Takashi, trans. Textbook of Sake Brewing. Tokyo: The Brewing Society of Japan, 2016.

Japan Awasake Association (website). Accessed February 22, 2024. https://awasake.or.jp/en/.  

Japan Sake and Shochu Makers Association. “Consecutive Record-High Growth in Sake Export Value and Volume in 2022.” Japanese Sake, February 23, 2023. https://japansake.or.jp/sake/en/topic/news/consecutive-record-high-growth-in-sake-export-value-and-volume-in-2022/.

Sake Service Institute. The Textbook for International Kikisake-shi. Tokyo: Sake Service Institute, 2018.

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