Kaso and Plant-Based Dashi for Modern Kitchens

Plant-based dashi roots in Japanese Buddhist shojin ryori, documented from the Kamakura period (12th–13th century); kombu cold extraction and shiitake dashi as formal shojin techniques formalised in the Urasenke and Omotesenke tea school cooking traditions; contemporary revival driven by vegan and plant-based dietary trends intersecting with Japanese culinary heritage

As plant-based and vegan cooking expands in Japan and globally, the concept of kaso dashi (flower-vegetable stock, a loose term for plant-based dashi) and the use of kombu, dried shiitake, dried gourd strips (kampyo), vegetable trimmings, and kelp-based broths as complete umami foundations — without any animal-derived ingredients — has become increasingly formalised and discussed. The traditional foundation for shojin ryori (Buddhist vegetarian cuisine) provides the most developed Japanese framework for this: kombu cold-extraction dashi, dried shiitake rehydration liquid, and occasionally dried lotus root or gobo as additional dashi contributors. The scientific basis for plant-based umami: kombu provides L-glutamic acid (approximately 1,600–3,000mg per 100g dried kombu); dried shiitake provides 5'-guanylate (GMP) at high levels after drying activates the enzymatic conversion; combining them creates the glutamate-guanylate synergy parallel to the glutamate-inosinate synergy of kombu and katsuobushi. A complete plant-based dashi system: primary kombu dashi (cold extraction), secondary shiitake dashi (rehydration liquid), and a third tier of vegetable stock from aromatic trimmings (negi green ends, shiitake stems, dried kombu scraps) simmered together at low heat. This three-tier system approaches the flavour complexity of traditional awase-dashi and is increasingly used by contemporary kaiseki chefs responding to dietary restriction requests. Shio koji and tamari (aged soy sauce with deep amino acid complexity) further extend the umami vocabulary of plant-based Japanese cooking.

Plant-based dashi flavour: clean, mineral from kombu, earthy and savoury from shiitake, supported by vegetable aromatics; the flavour is rounder and less sharp than fish-based dashi but has comparable depth when correctly prepared from high-quality kombu; the guanylate-glutamate synergy produces a distinct 'body' in the final broth