Shokupan Japanese Milk Bread Loaf

In a small saucepan, whisk together 20g bread flour and 100ml water until smooth. Cook over medium-low heat, stirring constantly with a whisk, until the mixture thickens to a paste-like consistency, similar to wallpaper paste, reaching 65°C (149°F). Remove from heat, transfer to a small bowl, cover with plastic wrap directly on the surface to prevent a skin from forming, and let it cool completely to room temperature. This will take about 30-60 minutes.

In the bowl of a stand mixer, combine the cooled tangzhong, remaining 300g bread flour, lukewarm milk, granulated sugar, salt, and instant dry yeast. Attach the dough hook and mix on low speed for 2-3 minutes until a shaggy dough forms. Increase speed to medium and knead for about 10 minutes until the dough starts to come together and is somewhat elastic.

Add the softened unsalted butter to the dough. Continue kneading on medium speed for another 10-15 minutes, or until the dough is smooth, elastic, and passes the windowpane test (a small piece of dough can be stretched thin enough to see light through it without tearing). The dough should be slightly sticky but manageable.

Form the dough into a ball and place it in a lightly oiled large bowl. Cover the bowl with plastic wrap or a damp cloth and let it rise in a warm place for 1 to 1.5 hours, or until it has doubled in size. The ideal temperature for rising is around 25-28°C (77-82°F).

Gently punch down the risen dough to release air. Transfer it to a lightly floured surface and divide it into three equal pieces. Roll each piece into an oval, then fold the top third down to the center and the bottom third up, pressing to seal. Turn the dough 90 degrees, then roll it into a cylinder. Place the three shaped dough pieces seam-side down into a greased 9x5 inch loaf pan.

Cover the loaf pan loosely with plastic wrap and let it rise in a warm place for another 45-60 minutes, or until the dough has nearly doubled in size and fills about 80-90% of the pan. Preheat your oven to 190°C (375°F). Brush the top of the risen dough with an egg wash (beaten egg). Bake for 30-35 minutes, or until the crust is golden brown. If the top browns too quickly, you can loosely tent it with aluminum foil. Remove from oven and immediately transfer the loaf to a wire rack to cool completely before slicing.