• If you are looking for a yeast version of pain de mie, check this no-knead pain de mie recipe out
• I use a small Pullman loaf pan that measures 9 x 4 x 4 inch. For recipe adjustment to fit a different loaf pan, please see my post below

Prepare the sweet stiff starter:

• I recommend using a starter that is at least two months old and consistently doubles or triples in 4-6 hours when you feed it at 1:1:1 ratio. Young starter will not give the best result
• Combine all ingredients for the sweet stiff starter in a bowl. Stir a bit to roughly combine and then use your clean hand to knead it. This is a stiff starter, it's like a dough. Make sure no pockets of dry flour are visible. Transfer to a large see-through container (plastic or glass is fine, preferably wide-mouth so you can get it out easier later). Loosely cover with the lid and let it ferment until triple in size

Prepare the dough:

• Put the milk in a saucepan and bring it just until it starts to simmer. Turn off the heat immediately. You don't want to boil the milk. If you have an instant-read thermometer, it should be around 170 F (77 C). Scalding the milk helps to deactivate the whey protein in the milk that interferes with gluten development. Let the milk cool down to lukewarm before using as we don't want to kill the natural yeast
  
• Place all ingredients and the stiff starter in a mixing bowl of a stand mixer fitted with a dough hook attachment. Use the hook to stir everything around a bit so when you turn the machine on, the flour won't fly around and wet ingredients won't splash
  
• Start with the lowest speed to mix things up and then increase to speed 2 and knead for about 5 minutes or until it forms a dough. If the dough is too dry to come together, you can add a bit of milk one teaspoon at a time.
• Knead at speed 4 for about 5-8 minutes or until the dough is smooth and elastic. If you slowly stretch a small amount of dough, it will not break and light can pass through, like a window pane. Proceed to first proofing
  

First proofing:

• Transfer to a lightly oiled bowl, cover, and proof at a warm place for 2 hours, about 78-82 F (26-28 C), the dough will not double in size. It probably only rises about 25% but that's okay. Sourdough starter is different from using commercial yeast. We are not aiming for the dough to double at this first proofing
  

Shaping:

• Grease your loaf pan on all sides for easier release after baking
• Deflate the dough by folding the dough towards the center to push all the air out. Round it up into a dough ball, cover and rest for 10 minutes to relax the gluten
• Lightly dust your work surface. Transfer the dough on it. Use a rolling pin to roll the dough out into a rectangle, roughly about 14 x 10 inches
  
• Fold both sides (shorter side) to meet at the center
  
• Then roll tightly into a log, roughly about as long as the pan. Pinch the dough to seal each time you roll to create tension and to make it tight. Push out as much air as you can to prevent big holes in the crumbs later
  

Final proof:

• Place the log inside the loaf pan. Push the dough down to fit the pan and to even out the dough.
  
• Cover and let the dough proof until it is about 1-inch below the rim if you plan to use the lid with your Pullman pan. Slide the cover close
  
• If you use 9 x 5 inch loaf pan, proof until the dough is about 1-inch above the rim
• The final proof may take somewhere around 3-4 hours at 78-80 F (26-27 C). Mine usually takes about 3- 3 1/2 hours at the mentioned temperature

Baking:

• 10 minutes before the end of final proofing, preheat the oven to 375 F (190C) for conventional oven, 350 F (180 C) for convection oven
• Put the pan in the oven's middle rack. Bake for 30 minutes if you use Pullman pan with the lid, then open the lid and bake for another 5 minutes. If you bake it in a regular pan, bake for 25-30 minutes or until the top is golden brown. Tent the loaf with aluminum foil if it gets dark before the end of cooking time. The internal temperature at the center of the bread should be at least 190 F (88 C)
  

Cooling:

• Gently wiggle the bread out of the pan and let it cool off on a cooling rack completely before slicing the bread

Storing:

• Let the bread cool down completely. You can keep them in an air-tight container for 3 days. They can also be kept frozen for up to 1 month in the freezer