Kasuzuke — Sake Lees Preservation (粕漬け)

Japan — kasuzuke developed alongside sake production, making use of the substantial volume of kasu produced as a byproduct. Narazuke from Nara (Nara's sake brewing tradition is over 1,000 years old) is among Japan's oldest documented fermented foods.

Kasuzuke is the pickling of fish, meat, or vegetables in sake kasu (酒粕) — the lees (pressed solids) remaining after sake is pressed from fermented rice mash. The kasu contains residual sugar, amino acids, yeasts, and alcohol; it acts simultaneously as a preservative, a flavouring agent, and a tenderising medium. The most celebrated kasuzuke: Narazuke (奈良漬け, from Nara Prefecture) in which vegetables are pickled in sake kasu for months to years; and sakekasu-marinated fish such as gindara no kasuzuke (black cod in sake lees), one of Nobu Matsuhisa's most celebrated dishes.

• Using fermented rice beverage lees as a marinade and preservative — makgeolli tenderises meat similarly to sake kasu → Makgeolli marination Korean
• Wine-making byproducts (marc, pomace) used as marinating agents; the residual alcohol, acids, and tannins perform similar preservation and flavour-transfer functions → Marc/pomace wine marination European

Kasuzuke delivers the concentrated flavour of sake — the fermented rice sweetness, the amino acid depth, and the alcohol's penetrating character — embedded into the food itself. Grilled kasuzuke fish develops an extraordinary caramelised crust from the sugar and amino acids, while the interior remains moist and infused with sake character. The flavour is simultaneously sweet, savoury, slightly alcoholic, and deeply umami — a uniquely Japanese combination of fermentation and Maillard reaction.