Sourdough Shokupan (Milk Bread) 76% Hydration

I’ll be honest, I had ChatGPT calculate this recipe for me. I prompted it for a 70% hydration on my first attempt and the bread turned out great. This time, I pushed for 76% — not much of a difference in taste but the spring is definitely better.

ROOM TEMPERATURE
74°F (23°C)

INGREDIENTS
Sweet Levain: (make the night before)
50g active sourdough starter
100g bread flour
10g sugar or honey

Main Dough:
All the sweet levain
250g bread flour
30g Sugar
4g Salt
1 whole egg (50g)
150g warm whole milk (I used leftover butter milk)
40g unsalted butter (room temp)

Egg Wash:
1 Egg
Dash of milk
1/2 tsp honey (optional)

KEY MILESTONES:
The time here varies. I started 8:00AM the next day and it was ready to bake around 4:00PM.

8:00PM (night before): Make the overnight levain.
6:30AM: Mix main dough. Autolyse for 30 min.
7:00AM: Knead for 25 min. I used a stand mixer with 2 min. interval rest and incremental increase in speed (level 1-5). Do a windowpane test. Place on a greased bowl and cover.
7:30AM – 12:30PM: Bulk ferment (mine tripled within 3-4 hours).
12:30PM: Shape dough. Make sure to flour every surface that touches the dough. Divide dough into 3 (use a weighing scale). Let it rest for 10 min. I used a Lodge 8.5”x4.5” bread pan with parchment paper. Grease the sides.
12:45PM – 5:45PM: Final proof (mine went over the rim within 3.5 hours).
6:00PM – 6:35PM: Bake. Preheat oven to 350°F (175°C). Brush egg wash on top. Bake for 30-35 min. until the inside temp is 195-200°F (90-93°C). If the top browns too quickly, cover with foil halfway through or when desired.
6:35PM+: Cool for 10 min. & enjoy!

I asked ChatGPT why it didn’t include the tangzhong. It said it wasn’t necessary for this recipe because of the high hydration, longer fermentation, extra milk and butter but suggested that tangzhong can be added if you want even more moisture or a longer shelf life. Definitely something to try next time.

More photos in the comments.