Japan (national; rice cultivation established from 3rd century BCE Yayoi period)
Rice polishing ratio (seimaibuai — 精米歩合) is the most important technical concept in Japanese premium rice culture, applying directly to both sake brewing and the increasingly sophisticated world of artisan table rice. Seimaibuai expresses the percentage of rice remaining after polishing: 100% = unpolished (genmai/brown rice); 70% = 30% of outer grain removed (standard table rice); 60% = ginjo sake threshold; 50% = daiginjo sake threshold; 23% = the current polishing extreme (used for ultra-premium sake). For table rice, recent artisan trends have returned to higher-seimaibuai (less polished) rice for greater flavour complexity and nutrition: haigamai (胚芽米) retains the germ but removes bran; zakkokumai (雑穀米) blends multiple grain types. Koshihikari (コシヒカリ) remains Japan's dominant table rice variety (approximately 35% of total production), prized for its stickiness, sweetness, and aroma. Premium regional varieties include Tsuyahime (Yamagata), Nanatsuboshi (Hokkaido), Hinohikari (Kyushu), and Milky Queen (Ibaraki). The annual rice quality competition (Nihon Ichi Umai Kome Concours) ranks varieties and growing regions annually.
Polished white rice: clean, lightly sweet, delicately starchy, cohesive; brown rice (genmai): nutty, earthy, toasted; haigamai: intermediate with subtle germ sweetness
{"Seimaibuai and flavour relationship: lower seimaibuai (more polished) = less protein and fat = cleaner, lighter flavour; higher seimaibuai = more bran = nuttier, earthier, more complex","Water ratio adjustment by polish level: brown rice (genmai) requires 1.5x water and longer soaking (overnight); haigamai requires 1.2x water; white rice requires 1.1–1.15x","Washing technique: wash premium table rice gently in cool water — first water absorbs fastest, discard immediately; subsequent washes until semi-clear; over-washing removes beneficial surface starch","Resting after washing: allow washed rice to drain and rest (suikyū) for 30 minutes before cooking — hydrates outer starch layer evenly for consistent texture","New vs old rice timing: shinmai (新米 — new crop rice, harvested October–November) has higher moisture content; requires slightly less water; superior sweetness and aroma compared to stored rice"}
{"Shinmai evaluation: premium shinmai (October harvest) from Uonuma, Niigata should be purchased within 6 weeks of harvest date for peak flavour — check the stamp on bags","Haigamai advantage: germ-retained rice delivers vitamin B1 and E naturally absent in white rice while preserving the familiar white-rice texture and flavour — an intelligent compromise","Sake rice vs table rice: Yamadanishiki, Omachi, and Gohyakumangoku are large-grained sake rice varieties unsuitable for eating (poor eating texture) but occasionally served at brewery restaurants as novelty"}
{"Washing rice too vigorously — breaking grains or over-washing removes the surface starch that creates desirable cohesion in cooked rice","Not adjusting water ratio for rice age — old rice (koma) is drier and requires up to 10% more water than shinmai","Lifting the lid during cooking — steam loss in the first cooking phase creates uneven moisture distribution and mushy patches","Skipping the steaming rest (mushirashi): 10–15 minutes resting after heat-off redistributes moisture from bottom to top of rice cooker — do not open lid during this period"}
Japanese Cooking: A Simple Art — Shizuo Tsuji / The Complete Guide to Japanese Drinks — Stephen Lyman