Add sourdough starter, water, honey, salt, and two cups flour to a stand mixer.
Mix until it comes together, about 10 minutes on low speed. The dough will be really stiff and difficult to incorporate.
Add remaining flour, half a cup at a time. Use a dough hook and knead until it is smooth and pliable.
Cover dough with wet tea towel, plastic wrap, or beeswax wrap and allow to ferment for 8 to 12 hours.
After fermentation, divide into 8 equal pieces.
Roll the dough into balls, flatten them down a bit, and poke a hole in the middle with your finger. Stretch the hole a bit to widen.
Cover with a tea towel and allow the dough to rise in a warm spot for 1-4 hours or until puffy.
Preheat oven to 425 degrees.
Bring a large pot of water to a boil and add the baking soda and sugar.
Using a slotted spoon, gently add bagels to the water and boil for one minute, flip, then boil for another minute.
Shake off excess water and dip into desired toppings (optional).
Place boiled bagels on parchment-lined baking sheet.
Bake for 15-25 minutes, or until golden on top. *Timing depends on your oven*