If there’s a hamburger show, a chewy and soft bun with a sourdough taste will be the star. Its spongy nature will soak up the burger juice, and at the same time, its firm structure keeps them from falling apart. Here’s how to make yours: 

Ingredients:

• 170g sourdough starter
• 170g of warm water
• 1 teaspoon instant yeast (optional)
• 240g All-Purpose Flour
• 27g  white whole wheat flour or Organic Medium Rye Flour
• 2 tablespoons potato flour
• 2 tablespoons Dry Milk or non-fat dry milk
• 1 1/2 teaspoons salt
• 1 tablespoon of granulated sugar
• 4 tablespoons of unsalted butter (softened)

Instructions:

• Combine the sourdough starter, yeast, and water in your mixer bowl.
• Next, combine dry milk, flour, salt, and sugar, then add the starter and water to the mixer bowl.
• Fit in your mixer bowl and then turn it on to the lowest speed. 
• Mix all the ingredients thoroughly for 2 - 3 mins to make a cohesive, sticky dough. 
• Turn the mixer off, scrape the bowl, and then switch to the dough hook. 
• Add butter, then turn the mixer up a speed or two, and continue kneading for about 8 - 12 mins until the dough is elastic and smooth.
• Cover and allow to rest in a warm place for 4 hours. 
• Place the dough onto a lightly floured work surface and divide into six equal pieces (each piece weighing about 120g)
• Shape each dough piece into tight balls and place them on a lightly greased baking sheet.
• Slightly flatten the balls by pressing them gently. Cover the buns for about 4 hours and let it rise until its puffy.
• Preheat the oven to 190°C before you bake.
• Uncover the buns and brush with beaten egg yolk mixture. 
• Sprinkle with toppings.
• Bake the buns for about 20 - 25 mins until they turn golden brown.