These sourdough buns with added potato are the perfect hamburger bun. Extremely soft with enough strength and structure to support anything you might be grilling.
- 61g all-purpose white flour
- 61g water
- 61g ripe sourdough starter
- 508g all-purpose white flour
- 203g potato, russet (about 3 medium; baked, riced, and cooled)
- 112g butter, unsalted
- 91g eggs
- 25g caster sugar
- 178g whole milk
- 11g sea salt
- 183g ripe levain
- 1 egg
- 1 tablespoon whole milk
A mix of white and black sesame seeds, if desired.
- Prepare levain and potatoes – 8:00 a.m.
In a small bowl, mix and knead the Levain ingredients. Transfer to a small container, cover, and keep it at a warm temperature for 3 hours. Preheat the oven to 350°F (178°C) with a rack in the middle. Grab three or four potatoes that together weigh at least 300g or so — you will need a little extra to avoid coming in short (I baked 3 and had a little leftover) and scrub the skin clean under running water. Place the whole potatoes into a small roasting pan or dish and, with a fork, prick the skin around the potatoes several times to allow them to breathe during baking. Bake the potatoes for about 1 hour, flipping them halfway through. Remove them from the oven when a knife can easily slide into the center of the potato (internal temp of 208-211°F / 98-99°C). When baked, remove from the oven, skin them and rice them onto a baking sheet to cool.
- Mix – 11:00 a.m.
To the bowl of a stand mixer fitted with the dough hook attachment, add all of the Main dough ingredients except the potato and butter (leave the butter at room temp to soften at this time). Turn the mixer to the lowest speed and mix until everything is incorporated. Scrape the sides of the bowl and dough hook and increase to speed 2, mix for 3-5 minutes until the dough begins to cling to the dough hook, and remove from the sides of the bowl. Then, scrape the hook clean, cover the mixing bowl, and let rest for 10 minutes. After the rest, mix on speed 2 for another 2-3 minutes until the dough again begins to cling to the hook. Next, add the room temperature butter, one pat at a time, while the mixer is set to low speed. Once all the butter is added, add half the riced potato and mix on low until incorporated. Then, add the remainder of the potato. Transfer the dough to a container for bulk fermentation.
- Bulk fermentation – 11:15 a.m. to 2:30 p.m. (about 3.5 hours)
This dough will need 3 sets of stretches and folds during bulk fermentation where the first set starts after 30 minutes into bulk fermentation and the subsequent sets are at 30-minute intervals. After the third set of stretches and folds, let the dough rest, covered, for the remainder of bulk fermentation.
- Divide and shape – 2:30 p.m.
To make shaping easier, place your bulk fermentation container into the fridge for 30 minutes. Line two baking sheets with parchment paper. After the dough is chilled, scrape the dough out to a floured work surface and divide into 120g potions. Using floured hands, flour the top of the dough pieces and shape them into tight balls. Place 5 on each baking sheet.
- Proof – 2:45 p.m. to 5:15 p.m. (2.5 hours)
Cover the baking sheets with large reusable plastic and seal shut and proof for about 2 1/2 hours until the dough has puffed up considerably and is very soft to the touch.
- Bake – 5:15 p.m., pre-heat oven at 4:45 p.m.
Preheat your oven to 450°F (232°C) with one rack at the bottom third and another at the top third. Make the egg wash: in a medium bowl whisk together one whole egg and 1 tablespoon of whole milk. Whisk until no lumps remain, and the mixture is frothy. Uncover your baking sheets and, using a pastry brush, paint on an even layer of the egg wash. Liberally sprinkle on black and white sesame seeds, if desired. Bake the dough for 25-30 minutes until well colored. When baked, remove and let cool for 5 minutes on the sheets, then transfer to wire cooling racks.
If you don’t have a potato ricer, mash the potatoes while still warm with a potato masher or fork.