Dassai Sake: How a Small Yamaguchi Brewery Rewrote the Rules of Premium Sake
Dassai sake became a global shorthand for premium sake not because it topped a ranking, but because a nearly bankrupt brewery in the Yamaguchi mountains bet everything on a single, narrow category: junmai daiginjo. That gamble, made in the 1980s, forced the rest of the industry to rethink how sake could be brewed, staffed, and sold beyond Japan. The more interesting part of the story, though, is what Dassai’s own team says about the numbers on its bottles — and why a high polish ratio was never meant to mean “the best.”
What Is Dassai, and Where Does It Come From?
Dassai is the flagship junmai daiginjo brand of Dassai Inc., a brewery based in the small mountain hamlet of Osogoe, in Shuto-machi, Iwakuni City, Yamaguchi Prefecture, about thirty minutes inland from central Iwakuni. The company traces its sake brewing back to the Sakurai family in the late 1800s and was formally established as Asahi Shuzo Co., Ltd. in 1948; in January 2025 it announced it would rename itself Dassai Inc. as of June 1, 2025, to match global recognition of the brand. For most of its history it was a small, unremarkable producer — the surrounding area is so rural that the local elementary school has counted only a handful of students at a time. You can find general background on the brewery alongside other producers in our brand index.
Why Did the Brewery Stop Making Everyday Sake?
In short: a near-bankruptcy forced a bet on quality over volume. When Hiroshi Sakurai took over as third-generation president in 1984 at age 34, the brewery was producing about 126 kiloliters a year (roughly 70,000 standard bottles) with annual sales of around ¥97 million, and it was, in his own account, on the verge of going under. Rather than keep selling Asahi Fuji, the brewery’s ordinary-grade sake with a 200-year history, Sakurai chose to abandon it entirely and focus on ginjo-grade brewing, and eventually on junmai daiginjo — sake made only from rice, koji, and water, with no added brewing alcohol, and milled down substantially before fermentation. Failure followed failure until 1990, when the brewery finally released a junmai daiginjo milled to 50% and 45% of the original grain size. Two years later came the sake that would define the company. Those figures sit against a legal backdrop: the labelling notification allows daiginjo only at a seimaibuai of 50% or less, so 45% and 23% are both inside the same legal band, far apart as they look (National Tax Agency Notification No. 8 of 1989).
What Do the Numbers on a Dassai Bottle Actually Mean?
The numbers — 45, 39, 23 — refer to seimaibuai, the rice polishing ratio: the percentage of each grain’s original size that remains after the outer layers, rich in fats, proteins, and minerals, are milled away. A lower number means more of the grain was polished off before brewing. Japan’s national labeling standard requires a seimaibuai of 50% or less for a sake to be called daiginjo, and Dassai’s entire catalog lives inside or beyond that threshold. Our glossary has a fuller explanation of seimaibuai and a separate piece on the science of why sake rice is polished in the first place, including how it affects aroma and clarity of flavor.
The brewery’s best-known expression, launched in 1992 under the older name Migaki Niwari Sanbu, is milled down to 23% — meaning 77% of each grain is removed before brewing even starts. According to Dassai’s own account of the sake’s development, the milling process for that ratio runs a continuous 168 hours, or seven days and nights, on the polishing equipment. The brewery’s own account of that first 23% run adds up to exactly that: six days and nights on the mill, then a further twenty-four hours to take the last two percentage points off (Dassai Inc., the story of Migaki Niwari Sanbu). Its published process page puts routine polishing at up to 144 hours.
| Label | Seimaibuai (rice remaining) | What it signals |
|---|---|---|
| Dassai 45 | 45% | Sits at the entry point of the line; more of the grain’s outer layers remain in the mix |
| Dassai 39 | 39% | A middle point between Dassai 45 and Dassai 23 |
| Dassai 23 | 23% | Milled for roughly a week straight; one of the most heavily polished sake made commercially |
It’s worth being precise here: these figures describe a production method, not a scoreboard. More on that below.
How Did Dassai Move Away from the Traditional Toji System?
The brewery replaced a centuries-old seasonal craft role with year-round, employee-run, data-backed brewing — and it happened somewhat by accident. Traditionally, sake is brewed under a toji, a master brewer who leads a team of seasonal workers, often farmers from snow-country regions, hired only for the winter production months; the toji would leave once brewing season ended, leaving the brewery owner to sell whatever had been made. In 1998, Asahi Shuzo’s toji told Sakurai he no longer wanted to make sake. Rather than replace him, Sakurai and his remaining staff broke the toji’s methods down into documented, repeatable steps and began brewing sake themselves, year-round — a practice known as shiki-jozo, or four-season brewing. That shift let the company scale production, respond to orders in real time, and standardize quality control in a way a once-a-year production cycle could not.
Should Heavy Rice Polishing or a Famous Name Mean “The Best” Sake?
No — a polishing ratio or a well-known name describes a sake’s style and production category, not an objective rank, and this is arguably the single biggest misconception about Dassai on the English-language web. It’s easy to read “23% polishing” and assume it must sit at the top of some quality ladder, especially since Dassai’s international visibility makes it many drinkers’ first exposure to daiginjo-level sake. But Dassai’s own team has pushed back on that reading directly, writing about Dassai 23: “we do not think this sake is great because it has the best polishing ratio… we are not to be satisfied with this figure, but are striving for Japan’s best, most delicious sake.” Heavy polishing tends to strip away the fattier, more mineral-heavy outer layers of the grain, generally producing a lighter, more fragrant, fruit-forward profile — not an automatically “superior” one. Plenty of experienced drinkers prefer honjozo or junmai sake milled to 60% or 70%, precisely because more of the grain remains, carrying more rice character and weight, in the same way a lightly oaked white wine isn’t automatically inferior to a heavily oaked one, or a delicate pilsner isn’t inferior to a dense stout.
Independent view: a polishing ratio printed on a label is a production spec, not a scoreboard — two sakes milled to the same percentage can taste completely different depending on rice variety, yeast, and brewing choices, and a 70%-milled junmai can outshine a 35%-milled daiginjo for someone who wants more rice character in the glass.
It also helps to know that Japan once had an official sake grading system — tokkyu (special), ikkyu (first), and nikyu (second class) — administered for tax purposes from 1943 until it was phased out between 1989 and 1992, replaced by the seimaibuai-based categories (honjozo, ginjo, daiginjo, junmai, and their combinations) used today. That older system really was a rank. The current one is a set of category definitions based on ingredients and milling — which is part of why treating “daiginjo” or “23%” as a substitute for a quality score misreads what the label is actually telling you.
How Did Dassai Become a Global Export Symbol?
Dassai’s international footprint grew in a fairly clear sequence: Taiwan in 2002, the United States in 2003, and, by the brewery’s own account, roughly 18 countries by the mid-2010s, including the UK, France, and Hong Kong. Sakurai had explicitly framed the domestic Tokyo market and international expansion as sequential necessities for a small, rural brewery with no built-in local customer base to fall back on. The clearest recent milestone came in September 2023, when the company opened Dassai Blue, its first brewery built outside Japan, in Hyde Park, New York — a roughly $80 million facility with the capacity to produce well over 100,000 cases annually using American-grown rice. In January 2025, the company announced a target of growing annual revenue from ¥19.5 billion to ¥100 billion, with ¥70 billion of that coming from overseas sales, alongside the move to rename itself Dassai Inc. (As of this writing, that revenue split is a stated target rather than a current figure, so treat it as forward-looking.)
- 2002: First export market, Taiwan
- 2003: Entry into the United States
- Mid-2010s: Sold in roughly 18 countries
- 2023: Dassai Blue brewery opens in Hyde Park, New York — the brand’s first overseas production site
- 2025: Company renamed from Asahi Shuzo Co., Ltd. to Dassai Inc., citing global brand strategy
Frequently Asked Questions
Is Dassai a brewery name or a sake name?
Both, in casual English usage. Dassai is the flagship junmai daiginjo brand made by the company now called Dassai Inc. (formerly Asahi Shuzo Co., Ltd.), based in Yamaguchi Prefecture.
What does “Dassai 23” mean?
It refers to a seimaibuai, or rice polishing ratio, of 23% — meaning 77% of each rice grain is milled away before brewing, a process the brewery says takes about a week of continuous polishing.
Is Dassai the “best” sake in Japan?
No single sake holds that title, and the brand doesn’t claim it either. Heavy polishing and international name recognition describe a particular style — light, aromatic, daiginjo-grade — among many valid styles that Japan’s roughly 1,000 sake breweries produce.
Does Dassai still use a traditional toji (master brewer)?
No. Since 1998, the brewery has brewed year-round using a documented, staff-run system rather than a seasonal toji, a departure from how most sake in Japan was historically made.
Where can I find Dassai outside Japan?
Availability has expanded steadily since exports began with Taiwan in 2002 and the U.S. in 2003, and the 2023 opening of the Dassai Blue brewery in New York added domestically produced sake to the U.S. market. Stock varies by country and retailer, so local availability is worth checking directly.
For more stories like this one — on the breweries, the science, and the misconceptions behind the sake in your glass — follow along at @thesakeanatomy on Instagram.
— Dr. Sake
Sources
- Dassai Inc. (株式会社獺祭, formerly Asahi Shuzo Co., Ltd.), Iwakuni, Yamaguchi Prefecture; founded 23 January 1948. Corporate information. Official page, Japanese
- Dassai Inc. Dassai Junmai Daiginjo Migaki Niwari Sanbu — Yamada Nishiki milled to a seimaibuai of 23%. Official product page, Japanese
- Dassai Inc. The story of Migaki Niwari Sanbu (獺祭磨き二割三分物語). Account of the first 23% milling: six days and nights, plus a further twenty-four hours for the final two percentage points. The company’s process page separately gives up to 144 hours for routine polishing. Official page, Japanese
- National Tax Agency of Japan. Standard for Manufacturing Methods and Quality Labelling of Sake (清酒の製法品質表示基準), NTA Notification No. 8 of 1989. Daiginjo requires a seimaibuai of 50% or less. Full text, Japanese
