Wagashi Yokan Summer Mizu-Yokan and Production

Ingredients

• 4 g Kanten (agar powder), weighed precisely
• 250 ml Water, cold, for dissolving kanten
• 300 g Koshian (smooth red bean paste), fully smooth; coarse tsubuan must not be substituted
• 80 g Sugar, plain white; yielding a 30–35% sugar ratio in the finished confection
• 1 pinch Fine sea salt, for finishing the cut surface at service; optional

Method

1. 1
   Measure the kanten powder into a small saucepan with 250 ml cold water. Set over medium heat and stir continuously until the powder is fully dissolved and the liquid comes to a gentle boil. The liquid must be clear and without undissolved granules — hold it briefly at the boil to ensure complete dissolution. Sight-test: the liquid is uniformly clear with no clouding or sediment.
2. 2
   Add the sugar and stir until fully dissolved into the kanten liquid. Reduce the heat to low. Add the koshian in stages, incorporating each addition fully before the next. Beat the paste thoroughly into the liquid until the mixture is completely homogeneous with no white streaks or unmixed paste. This step decides the dish: incomplete incorporation produces white spots and uneven flavour distribution through the set gel — the mixture must be smooth, uniform in colour, and without visible separation before it leaves the heat.
3. 3
   Remove from heat. Pour immediately into a square mould rinsed with cold water. Work without delay — kanten begins to set as it cools. Tap the mould gently on the work surface to level the surface and release any air pockets. Sight-test: the surface is flat, smooth, and free of bubbles.
4. 4
   Allow the mould to cool to room temperature, then cover tightly and transfer to the refrigerator. Refrigerate for a minimum of four hours. The gel must be fully set before cutting — less than four hours produces crumbling edges. Touch-test: the surface springs back cleanly under light pressure and does not adhere to the finger.
5. 5
   To unmould, run a thin blade around the inner edge of the mould and invert onto a clean board. To cut, wet the knife blade with cold water before each cut — a dry blade drags against the agar and tears the surface. Cut into rectangular portions. Sight-test: each cut face is clean, smooth, and precise with no crumbling or dragging.
6. 6
   Serve directly from the refrigerator, as cold as possible. If using, apply a pinch of fine sea salt to the cut surface immediately before service. The mizu-yokan must be eaten cold — the thermal contrast with summer heat is the experience. Taste-test: the flavour is cool, barely sweet, and delicately of red bean, with a clean agar-neutral quality and no heaviness.