Japanese Konnyaku and Shirataki: Konjac Devil's Tongue Preparations
Japan — nationwide, konjac cultivation centred in Gunma Prefecture
Konnyaku (蒟蒻, konjac or devil's tongue jelly) is one of the most distinctive ingredients in the Japanese culinary canon — a firm, slightly gelatinous cake made from konjac flour (glucomannan extracted from Amorphophallus konjac tubers). It has essentially no calories (approximately 5kcal per 100g), no fat, and almost no flavour of its own, yet its texture — firm, slightly bouncy, with a surface that holds sauces and absorbs seasonings from the outside while remaining dense and resilient within — makes it irreplaceable in Japanese simmered dishes. The texture is produced by mixing konjac flour with water and calcium hydroxide (lime water), which causes the glucomannan gel to irreversibly set — it cannot be melted back once formed. Konnyaku is produced in two primary forms: grey/speckled blocks (which contain nori or hijiki seaweed particles giving the traditional appearance) and white blocks. Shirataki noodles are konnyaku extruded into noodle format. Key preparations: oden (winter hotpot), sukiyaki and shabu-shabu, dengaku (grilled on skewers and topped with miso paste), and nimono (simmered dishes). The surface should be scratched or torn rather than cut for nimono — the rough surface absorbs broth more effectively.