Kuzu-Kiri and Kuzumochi: The Arrowroot Starch Preparations of Japanese Summer Dessert Culture

Ingredients

• For the kuzu-kiri
• 100 g hon-kuzu (Yoshino arrowroot starch), true kuzu only — not potato starch or cornstarch
• 700 ml cold water, cold, for dissolving the kuzu
• For the kuromitsu
• 100 g kokuto (Okinawan or Amami black sugar), coarsely broken; refined brown sugar is not an acceptable substitute
• 80 ml water

Method

1. 1
   Make the kuromitsu first so it is cool at service. Combine the kokuto and water in a small saucepan over low heat. Stir until the sugar is fully dissolved, then simmer briefly until the syrup is slightly thickened and coats the spoon. Remove from the heat and allow to cool completely. The syrup is ready when it is deep mahogany-brown, glossy, and pours in a slow ribbon.
2. 2
   Place the hon-kuzu in a heavy saucepan. Pour all 700 ml of cold water over the starch. Stir thoroughly until every particle is dissolved and no white lumps remain. The liquid will appear milky-white and slightly viscous. Do not apply heat before the starch is fully dissolved in cold liquid — adding kuzu to hot liquid creates lumps that cannot be smoothed.
3. 3
   Set the saucepan over medium heat. Stir constantly with a heatproof spatula, scraping the base and sides of the pan, for 8–10 minutes. The mixture will first thicken, then become opaque and paste-like, and finally — as full gelatinisation is reached — shift to a clear, glossy, transparent gel. This is the step on which the dish lives or dies: an opaque gel means the starch is under-cooked and will carry a raw, starchy flavour; only when the gel is completely transparent throughout has full gelatinisation been achieved.
4. 4
   Working immediately, pour the hot transparent gel into a flat tray in an even layer. Set the tray into a bath of cold water — or ice water — and leave undisturbed for 20 minutes. The gel is ready when it is firm, cohesive, and pulls cleanly away from the tray with gentle pressure at the edge.
5. 5
   Turn the set kuzu slab out onto a board. Using a sharp knife, cut the gel into noodle-like strips of uniform width. Transfer the strips to a bowl of cold water. They should float freely, separate from one another, and present a high gloss and full translucency.
6. 6
   Divide the kuzu-kiri strips among four bowls, each filled with fresh cold water. Serve the cooled kuromitsu alongside in individual dipping bowls. The strips must be served cold; a warm kuzu gel is soft and loses all textural character. Diners lift individual strips, dip in kuromitsu, and eat at once.