Sourdough baps are the ultimate burger buns (yes, we said it!)

The Perfect Loaf is a column from software engineer-turned-bread expert (and Food52's Resident Bread Baker), Maurizio Leo. Maurizio is here to show us all things naturally leavened, enriched, yeast-risen, you name it — basically, every vehicle to slather on a lot of butter. Today, an explainer on baps, a bun you'll want to use to house sausage, eggs, and burgers alike.

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Baps are soft, leavened rolls, typically eaten for breakfast in the United Kingdom — but I find they also serve as a pretty stellar hamburger or egg sandwich bun. The distinction between a bap and bun you'd typically use for a burger seems to primarily revolve around the fat used in the recipe, with some claiming a true bap must be made with lard.

I choose to take a different stance. Baps and American-style hamburger buns are long-lost siblings: Both are less like a roll (which is typically much softer and serve as an accompaniment to a meal) and more like a sturdy vehicle for sandwiching fillings, essentially becoming a main dish when combined. But where baps are typically lighter in color, not excessively buttery, and topped with a dusting of flour, buns are usually darker, glossy, and sometimes topped with seeds.

The terminology and distinction between buns, rolls, baps, and so many more bready things shaped like a log or sphere are blurred, and usually steeped in tradition or culture. I think that's awesome! Depending on your location, the definition of each varies and they're all different interpretations of a soft, leavened piece of dough that's baked and meant to be sliced. To me, a bun — and bap! — is something that is meant to hold another piece of food when eating, whereas a roll is usually eaten as an accompaniment.

However, regardless of whether you call your bun a bun or your bun a bap (or, dare I say, it's important they're soft, but not too soft, so that they can serve as sturdy support for sandwiches and burgers of all varieties, and most importantly, that they're delicious.

Let's look at a few different types of buns, how they compare to baps, and the characteristics of each.

Baps vs. Brioche Buns

To be characterized as "brioche," a recipe typically contains at least 30% — and usually 50% or more — butter to total flour weight, plus a good measure of egg. The increased butter percentage, and its property which inhibits gluten strengthening, in brioche dough is what leads to its extremely tender and "shreddy" texture. This ensures the dough never gets overly strong, even after many minutes of mixing. The more butter you work into a dough, the softer and richer it will become.

A bap, by contrast, can have butter or lard added to the dough, but it's commonly in a smaller percentage. The goal for a bap is less about that buttery richness and more about that soft-but-not-too-soft texture. The reduction in richness makes them lighter overall, less decadent, yet more utilitarian. To me, this makes the bap a much more versatile bun for breakfast, lunch, or dinner.

Baps vs. Potato Buns

Another common bun style involves our starchy tuber friend, the potato. Adding cooked and mashed potato is one of my favorite ways to bring a high level of softness to a bun. Using potato flour is one approach, but my preferred method is to simply bake or microwave a potato, mash the flesh, then work that into the dough during the end of mixing.

The starches in a potato bring a luxuriously silky texture to the final bun, one that's different from adding fat such as butter or oil. Potato starch does act similarly to fat in that it inhibits gluten development, but it's also able to hang on to high levels of water. These starches then pull double duty to bring softness and moisture to the final bun.

Texturally, I also find potato buns to be much more filling than a bap. The added starch from the potato, while increasing softness, also increases the density of the bun. A potato bun with a hefty hamburger patty sandwiched between two halves typically imposes a one hamburger cap per person, and who wants to be limited like that?

At the heart of it, the difference between baps and potato buns is simply the fact that baps do not traditionally include any potato in the dough. While both are wonderfully soft and supple in their own way, once you introduce mashed potato into a dough you exit bap territory and firmly enter potato bun territory. Still, while many potato buns are topped with sesame seeds, in some recipes, you'll find the buns are dusted with flour just before baking, similar to how baps are prepared.

Since we're on the topic, let's talk about toppings and milk and egg washes.

Washes and toppings

We can't talk about buns and baps without addressing what is one of the most striking differences for me between a bun and a bap: Baps are traditionally dusted with white flour before baking. This dusting somehow enhances their soft and pillowy nature.

In addition to the flour topping, baps are usually a shade, or more, lighter than usual hamburger buns — and this is due to the wash used before baking, if there is one.

Photo by Maurizio Leo

In the image above you can see the results of my tests with various washes when developing a sourdough bap recipe. The two baps at the far left have no wash, the middle has only a whole milk wash, and the far-right have whole milk and whole egg wash. As expected, the gradient is evident, going from dullest at the left, to shiniest at the far right. But the goal for these baps isn't to have a glistening surface, we actually want a duller appearance. In the end, I preferred going with the middle ground: I brushed the baps with whole milk before dusting them with flour to give them a little extra color, but not too much, though you can go with whichever is most appealing to you.

In the end, I think buns, baps, rolls, flatbreads, and so many other small carb-based treats, stem from the common desire to have a piece of bread at the dinner table. The differences between them are nuanced, but that's commonly the case with baked goods, because they've arisen through time and are steeped in myriad cultures. Personally, I'm happy to have a bap or a bun at every meal — regardless of what they're called.

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Recipe: Sourdough Baps

Prep time: 25 minutes
Cook time: 35 minutes
Makes: 8 baps

Ingredients

Levain

• 57 grams bread flour
• 57 grams water
• 23 grams ripe sourdough starter (100% hydration)
• 11 grams caster or superfine sugar

Dough

• 518 grams bread flour, plus more for dusting
• 310 grams water
• 64 grams vegetable or canola oil
• 42 grams caster or superfine sugar (or granulated sugar if that's all you have)
• 11 grams fine sea salt
• 1/4 cup whole milk, or 1 large egg and 1 tablespoon milk, for wash (optional)

Directions

1. Make the levain (9:00 p.m.)

   In the evening, when your sourdough starter is ripe (when you'd typically give it a refreshment), make the levain. In a large-size jar (this levain will rise relatively high, so be sure to give it plenty of headspace), combine 57 grams bread flour, 57 grams water, 23 grams ripe sourdough starter, and 11 grams caster sugar. Cover the jar loosely and let the levain ripen overnight at warm room temperature (I keep mine around 74 to 76°F/23 to 24°C).
    

2. Mix the dough (9:00 a.m.)

   To the bowl of a stand mixer fitted with the dough hook attachment, on low speed, mix the 518 grams flour, 310 grams water, 42 grams caster sugar, 11 grams salt, and the ripe levain until combined and no dry bits of flour remain. Increase the mixer speed to medium-low and mix for 3 to 5 minutes, until the dough clumps around the dough hook. This is a firm dough at this point until we begin to add the oil after a rest.

   Let the dough rest for 10 minutes in the mixing bowl, uncovered.

   It will take several minutes to mix in all the oil for these baps. Turn the mixer on to low speed and begin to add the vegetable oil, about a teaspoon at a time, while the mixer is running. Patiently add more oil only as the previous addition has been absorbed. While mixing, continue adding all the oil until the dough smooths out and holds together in a cohesive mass.

   Transfer the dough to another large bowl or container for bulk fermentation.
    

3. Bulk ferment the dough (9:30 a.m. to 1:00 p.m.)

   Cover the dough with a reusable airtight cover and let it rise at warm room temperature (76°F/24°C) for a total of 3½ hours. During this time, you'll give the dough three sets of "stretches and folds" (see next step for explanation) to give it additional strength. The first set is performed 30 minutes after the start of bulk fermentation, and subsequent sets at 30-minute intervals, then the dough will rest for the remaining 2 hours. Set a timer for 30 minutes and let the dough rest, covered. After 30 minutes, give the dough its first set of stretches and folds.

   For each set of stretches and folds: With wet hands, grab the north side (the side farthest from you) of the dough and stretch it up and over to the south side. Then, in the same way, fold the south side up to the north. Then, perform two more folds, one from east to west, and one west to east.

   After performing the three sets of stretches and folds, let the dough rest, covered with the same airtight cover, in the bulk fermentation container for the remainder of bulk fermentation.
    

4. Shape the dough (1:00 p.m.)

   This dough can be proofed on a parchment or silicone-lined full sheet pan (18x26-inches) or two half-sheet pans (13x18-inches). Uncover the bulk fermentation container and lightly flour the top of the dough. Using a bowl scraper, gently scrape the dough out to your work surface. Then, using a bench scraper, divide the dough into eight equal portions (each weighing about 125 grams). Using the bench scraper in one hand, shape each portion into a very tight ball with a seam on the bottom. I like to use my bench scraper at a 45° angle to the work surface to push the dough against the surface, creating tension along the sides and top of the piece of dough. Once shaped, transfer the piece to the prepared sheet pan.
    

5. Proof the shaped dough (1:30 p.m. to 3:30 p.m.)

   Cover the sheet pan with a large reusable piece of plastic or bag and seal shut. Proof the dough at a warm temperature (74 to 76°F/23 to 24°C is ideal) for about 2 hours. The dough is ready to bake when it has puffed up, feels light and airy, and a gentle poke springs back very slowly. If there is any resistance felt in the dough when poked, let it proof for another 15 minutes and check again.
    

6. Bake the baps (3:30 p.m.)

   Position a rack in the middle of the oven; heat the oven to 425°F (220°C).
   Pour the 1/4 cup of whole milk (or whisk the egg and 1 tablespoon whole milk) into a small bowl and gather a pastry brush. Additionally, gather a small amount of bread flour and a fine sieve to dust flour on the top of the rounds. 
   Once the oven is preheated, use the pastry brush to brush on a thin layer of milk or egg wash onto each round. Then, use the sieve to tap out a light dusting of flour onto the round. Alternatively, skip the wash and simply dust the baps with flour.

   Bake for 20 minutes. After 20 minutes, rotate the pan back to front, reduce the oven temperature to 350°F (175°C), and bake for an additional 15 to 20 minutes, until the baps are golden.

   Once the baps are baked, remove them from the oven and transfer them to a cooling rack. Let them rest for 30 minutes before slicing.