— COLUMN / Guide
The Art of Milling — What the Polishing Ratio Actually Tells You
Seimaibuai is one of sake's most cited statistics. Here's what it genuinely tells you — and what it doesn't.
2026年3月11日
No number appears more frequently on premium sake labels than the seimaibuai — the rice polishing ratio. “Polished to 35%” reads one label; “50%” reads another. The implication seems clear: lower means better. The reality is more interesting.
What the Number Means
The seimaibuai expresses how much of the original rice grain remains after milling. A seimaibuai of 35% means 65% of each grain has been removed; 50% means half has been removed; 70% means only 30% has been milled away. The milling machine grinds slowly — taking 60, 70, sometimes 100+ hours to achieve extreme polish levels.
Why Rice Is Polished
The outer layers of a rice grain contain proteins, lipids, and minerals that contribute off-flavors to sake — what brewers call “zatsumi” (miscellaneous flavors). Polishing removes these layers, leaving a purer starch core that produces cleaner, more fragrant sake. This is why daiginjo (50% or below) tends to be more aromatic and refined than ordinary sake.
The Limits of the Logic
The “lower = better” equation breaks down at two points.
First, extreme polishing removes too much: the rice loses character, and the sake can become bland — clean but hollow. Some breweries cap their polishing at 40–45% not because they can’t go lower, but because they’ve found that additional milling removes more than it adds.
Second, the “low polishing ratio” movement argues that deliberately minimal milling (70–80%) preserves the full nutritional complexity of the rice — proteins, fats, minerals — which create genuine flavor depth. Breweries like Takachiyo (with their “59’” series, polished to 59%) and several natural sake producers have built their identities around this philosophy.
Seimaibuai as One Data Point Among Many
The seimaibuai tells you about production method and classification eligibility. It does not tell you whether you will enjoy the sake. A 70% polished junmai made from exceptional rice by a skilled brewer can be far more interesting than a 35% daiginjo made from mediocre ingredients by a brewery optimizing for competition scores. Use seimaibuai as a map reference, not a destination.