Japanese Shottsuru and Ishiru: Regional Fish Sauce Traditions of Akita and Ishikawa

Japan — Shottsuru: Akita Prefecture (Tohoku); Ishiru: Ishikawa Prefecture (Noto Peninsula)

Japan possesses its own indigenous fish sauce traditions predating Southeast Asian influence — regional condiments produced by fermenting whole small fish in salt that are among Japan's most distinctive and least-known fermented ingredients internationally. Shottsuru from Akita and ishiru from the Noto Peninsula of Ishikawa Prefecture represent two approaches to the same principle: protein enzymatic hydrolysis under salt producing amino-acid-rich, pungent liquid condiments with extraordinary umami depth. Shottsuru (from 'shottsu', the local name for sandfish — hatahata in standard Japanese) is made from sandfish (Arctoscopus japonicus), an Akita speciality that spawns in large numbers on Akita's Sea of Japan coast from November to December. Fresh sandfish are layered with salt at 30-40% salt ratio in wooden barrels and left to ferment for 1-3 years. The high-salt, cold-climate fermentation produces a pale amber, clean fish sauce with subtle, clean flavour character — less pungent than Southeast Asian fish sauces due to sandfish's white flesh. Shottsuru is most famously used in Akita's kiritanpo nabe hot pot, where it seasons the dashi together with soy sauce and mirin, but it functions as a universal umami seasoning for any application. Ishiru (or ishiri) from Ishikawa Prefecture is produced from the offal (primarily viscera) of squid (surume ika) or the whole small fish (iwashi sardine), producing a darker, more robustly flavoured sauce than shottsuru. The Noto Peninsula's coastal fishing culture and traditional preservation methods have maintained ishiru production through centuries of local use. Both sauces represent the third pillar of Japan's umami triumvirate (alongside shoyu and miso) in their respective regional cuisines. The historical depth of Japanese fish sauce tradition extends further: archaeologists have found evidence of gyosho (fermented fish pastes) in Nara Period sites, suggesting fish sauce traditions predating the development of both shoyu and miso in Japan. Understanding these regional sauces contextualises the global history of fermented fish condiments and positions Japanese umami culture within the broader fermentation tradition.

• The global fermented fish sauce family — Japanese gyosho traditions are the East Asian members of this category, sharing the salt-protein enzymatic hydrolysis mechanism while producing distinct regional flavour profiles → Nam pla/nuoc cham/prahok fish fermentation Southeast · Asian
• Ancient Roman garum and the modern European garum revival replicate the same chemistry as Japanese fish sauces — contemporary restaurant fermentation programs often bridge these traditions deliberately → Garum fermented fish sauce Roman/European
• Korean liquid fish sauces used as kimchi seasoning and general condiments — the closest regional parallel to Japanese shottsuru/ishiru in terms of production method and culinary application → Aekjeot (saeujeot liquid, myulchi aekjeot sardine sauce) Korean

Shottsuru: clean, delicate, transparent umami with subtle marine notes; ishiru: more robust, pungent, complex depth — both function as background umami amplifiers rather than dominant flavour elements