Wagashi Recipe

Soak and cook beans

If using dried white beans, rinse 1 cup thoroughly. Soak in 3–4 cups cold water for at least 6 hours or overnight. Drain. Place beans in a pot with fresh water to cover by about 2 inches (approximately 4 cups). Bring to a simmer, skim foam, then lower heat and simmer gently until beans are very soft and collapsing when pressed with a spoon, about 45–60 minutes. If using canned beans, skip soaking and simmer canned beans 10 minutes to soften and remove can flavor, then drain.

Puree and strain

Drain cooked beans, reserving about 1/2 cup of the cooking liquid. Purée the beans in a blender or food processor with 3 tablespoons sugar and up to 1/4 cup reserved cooking liquid (or water) until very smooth. Pass the purée through a fine-mesh sieve into a bowl, pressing to remove any skins or fibers for a silky paste.

Cook to make shiro-an

Transfer the sieved purée to a nonstick pan over low-medium heat. Add the remaining 4 tablespoons sugar and 1 teaspoon salt. Stir constantly to prevent sticking. Cook until the paste thickens and becomes glossy, about 6–8 minutes. If paste is too stiff, add up to 1 tablespoon water. Remove from heat and stir in 1 teaspoon neutral oil if using. Let cool to room temperature.

Make strawberry purée

Place 1 cup chopped strawberries, 1 cup water, 3 tablespoons sugar, and 1 teaspoon lemon juice in a small saucepan. Bring to a simmer over medium heat, stirring to dissolve sugar. Cook 3–4 minutes until strawberries soften and flavor concentrates. Remove from heat and cool slightly, then purée with an immersion blender or in a blender until smooth. Strain through a fine sieve to remove seeds, pressing to extract as much liquid as possible. You should have roughly 1 cup of smooth purée/juice.

Bloom agar and cook

Return the strained strawberry liquid to the saucepan. Sprinkle 2 teaspoons agar-agar powder evenly over the surface and let bloom for 2–3 minutes. Gently bring to a boil, whisking to dissolve the agar completely. Once boiling, reduce heat and simmer 1–2 minutes while stirring to ensure agar is fully dissolved. Taste and add additional sugar up to 1 tablespoon if you prefer a sweeter jelly.

Mold thin color layer

Pour a thin layer (about 1–2 mm) of the hot strawberry agar mixture into lightly oiled small round molds or onto a sheet of silicone to create a thin translucent colored disk. Allow to cool and set at room temperature (about 15–20 minutes) until firm but slightly tacky. These thin disks will form the colored inner/outer layer of the kohakutō pieces. Keep the remaining hot jelly warm for the next step.

Make small strawberry cores

If you want a fully strawberry interior center, pour small amounts (about 1/2 teaspoon) of the remaining strawberry agar into tiny molds to make miniature cores, or pour into a shallow tray to set and cut into small cubes. Chill briefly until set (10–15 minutes).

Shape shiro-an rounds

Divide the cooled white bean paste into 12 equal portions (about 20–25 g each). Lightly oil your hands or dust with a little potato starch (or use lightly oiled plastic wrap). Flatten each portion into a disk about 2–3 cm wide and 3–4 mm thick.

Encapsulate strawberry jelly

Place a small strawberry jelly core or a small dollop (about 1/4 tsp) of the still-warm but not hot strawberry agar onto the center of each shiro-an disk. Quickly cover with another thin disk of shiro-an or fold edges to seal into a ball, smoothing seams. For an airy kohakutō look, you can enclose a tiny air pocket by not pressing the paste completely flat—this will create internal translucency against the jelly. Work quickly before the agar fully sets.

Chill to set

Place assembled pieces on rice paper or plastic wrap on a tray. Chill in the refrigerator for 15–20 minutes to let the strawberry agar completely firm inside and for the bean paste to set its shape.

Make sugar syrup for crystallization

Combine 1 cup granulated sugar and 1 tablespoon water in a small heavy-bottomed saucepan. Heat gently just until the sugar dissolves and the mixture becomes a clear syrup (do not caramelize). Remove from heat and allow to cool to warm (not hot).

Coat and crystallize

Using tweezers or clean hands, lightly brush or dip chilled wagashi pieces briefly into the warm sugar syrup to moisten the exterior. Immediately roll the moistened pieces in extra granulated sugar (or place on a tray and sprinkle sugar generously) so a thin layer of sugar adheres. Arrange coated pieces on a rack or tray lined with parchment with space between them. Let them sit at room temperature for 12–24 hours; during this time the sugar layer will dry and form the characteristic faceted, crystal-like surface of kohakutō. For a lighter dusting of color, sift a little freeze-dried strawberry powder over the coated pieces before crystallization dries.

Finish

After crystals form, gently tap off any loose sugar. Store kohakutō in an airtight container with paper between layers at cool room temperature for up to 3–5 days. Avoid refrigeration after crystallization as humidity will soften the crystals.

Arrange kohakutō pieces on a clean plate or in individual paper cups. Optionally dust with a tiny pinch of freeze-dried strawberry powder for extra color. Serve at room temperature to appreciate the contrast between the airy bean paste, translucent strawberry jelly, and crunchy sugar crystals.