Step 1: Feed your sourdough starter 4-6 hours before you plan to mix the dough, ensuring it’s active and bubbly.
Step 2: In the bowl of a stand mixer, combine the active sourdough starter, warm water, bread flour, and salt. Mix with the dough hook on low speed for 8-10 minutes until the dough is smooth, elastic, and pulls away from the sides of the bowl. It should be stiff.
Step 3: Transfer the dough to a lightly oiled bowl, cover it, and let it bulk ferment at room temperature for 3-4 hours, performing a series of stretch and folds every 30-45 minutes for the first 2 hours.
Step 4: After bulk fermentation, gently turn the dough out onto a lightly floured surface. Divide the dough into 12 equal pieces (approximately 80-90g each) using a bench scraper.
Step 5: Shape each piece into a tight ball, then poke a hole through the center with your thumb. Gently stretch the hole to about 1 inch in diameter, creating a bagel shape. Repeat for all pieces.
Step 6: Place the shaped bagels on a baking sheet lined with parchment paper, leaving some space between them. Cover loosely with plastic wrap and refrigerate overnight for 12-18 hours for the cold proof.
Step 7: The next morning, preheat your oven to 450°F (230°C) with a baking stone or steel inside if you have one. Bring a large pot of water to a rolling boil, adding the barley malt syrup or honey.
Step 8: Gently drop 2-3 bagels into the boiling water at a time (do not overcrowd). Boil for 1 minute per side. Remove with a slotted spoon and place back on the parchment-lined baking sheet.
Step 9: If desired, sprinkle your chosen toppings (everything bagel seasoning, sesame seeds, poppy seeds) onto the bagels immediately after boiling.
Step 10: Bake the bagels for 18-25 minutes, or until they are golden brown and have a firm, chewy crust. If using a baking stone, slide the parchment paper directly onto it. Rotate the baking sheet halfway through for even baking.
Step 11: Once baked, transfer the sourdough bagels to a wire rack to cool completely before slicing and serving. Enjoy them fresh or freeze for later!