These sourdough buttermilk biscuits are my favorite twist on a southern classic! They're tender and buttery on the inside with a slightly crispy exterior and hundreds of perfectly flaky layers!
Place the butter in the freezer for at least 20-30 minutes before grating. Use a box grater to carefully grate the butter into small pieces. Keep the grated butter in the freezer until you're ready to use it. If you don't want to use grated butter, just cut the butter into small chunks and keep chilled until ready to use.
Line a baking sheet with parchment paper and set aside.
In a medium bowl, whisk together the flour, baking powder, sugar, and salt.
Add in the frozen grated butter and toss gently in until it's fully coated in the flour.
In a small bowl, whisk together the sourdough discard and buttermilk.
Then slowly drizzle the wet ingredients over top, combining as you go. Knead a few times in the bowl until you have a very dry, shaggy dough.
Turn the dough out onto a clean surface and gently pat the dough into a large 1 inch thick square.
Using a bench knife, cut the dough into 4 equal squares and then stack them on top of each other, making sure to sandwich any loose dry bits of dough between the layers.
Then flatten the stack of dough back into a large 1 inch thick rectangle. [This method of cutting and stacking the dough is what helps give the biscuits those super flaky layers!]
Use 2 ½ inch round biscuit cutters to cut out the biscuits, then reshape the dough scraps to cut out more biscuits. You should get 10-12 biscuits.
Transfer the biscuits to a parchment lined baking sheet and place in the freezer for at least 30 minutes before baking. Tip: Place the biscuits close together on the baking sheet so that the sides are nearly touching. This helps them rise even higher!
While the sourdough biscuits are freezing, preheat the oven to 425°F.
Remove the biscuits from the freezer and lightly brush the tops with buttermilk and sprinkle with flaky sea salt.
Bake at 425°F for 18-22 minutes or until the tops are golden brown.
Remove from the oven and enjoy the flaky sourdough buttermilk biscuits while warm!
Notes
These sourdough buttermilk biscuits are best eaten the same day, but they'll keep in an airtight container at room temperature for up to 3 days. You can also reheat biscuits in the oven at 350°F for 5-10 minutes.