Melt butter in a saucepan over medium heat. Cook, stirring occasionally, until it foams, sizzles, and golden brown bits form at the bottom. Once it smells nutty and turns deep golden, remove from heat and transfer to a heat-safe bowl to cool.
Add the water and starter to a large mixing bowl and mix well.
Add browned butter, sugar, flour, and salt; mix until no dry bits remain. Use a bowl scraper and scrape down the sides so everything is fully incorporated. Cover the bowl with plastic wrap and let the dough rest for 30 minutes.
Turn the dough out onto the counter and knead for 8-10 minutes. Use a bench scraper as needed to keep the counter clan. The dough should become smooth, elastic and slightly tacky. Place it back in the bowl, cover with plastic wrap, and let it rise at room temperature until doubled (8–12 hours, depending on your kitchen temp).
Once the dough has doubled in size, is jiggly, and has visible bubbles, it’s time to shape. Turn the dough out onto the counter using a bowl scraper and gently press out the air. Using your kitchen scale, divide the dough into 8 equal pieces. Shape each piece into a ball, creating tension without tearing. Let the dough rest for 10-15 minutes.
Poke a hole in the center of each ball with your finger, then gently stretch it to widen the hole. Flip the dough smooth-side down and place onto your counter. Working around the ring, use your fingertips to gently pinch the edges of the dough together. This helps even out the shape and build surface tension for a better final rise. Place each shaped bagel seam-side down on an individual pieces of parchment paper and then place them on a baking sheet. Cover with plastic wrap and let bagels rise somewhere warm for 1-3 hours until nice and puffy.
Preheat the oven to 425°F (220℃). Bring a large pot of water to a boil, then add baking soda. Working in batches to prevent crowding your pot, carefully lower a few bagels with the individual parchment still attached, into the water. Boil for 45 seconds to 1 minute, then flip using a slotted spoon. Use tongs to remove the parchment paper and boil the other side for another 45 seconds to 1 minute. Transfer the boiled bagels to a parchment-lined baking sheet. Repeat with remaining bagels.
Bake at 425℉ (220℃) for 20-25 minutes, or until the bagels are golden brown and the crust feels firm. For even browning, you can rotate the baking sheet halfway through. Once baked, transfer the bagels to a wire rack and let them cool for at least 15-20 minutes before slicing.