In a stand mixer, combine the starter, flour, salt, and water. Mix on low speed (number 2 for a kitchen aid mixer) for about 10 minutes or until the dough is pulled from the sides and not sticking.
This can be done without a stand mixer but will be much more difficult. You'll have to knead by hand for about 15 minutes or more until the dough has formed into a smooth ball and is not sticky.
Place the dough in a greased bowl, cover with plastic wrap, and let it rise at room temperature for 8-10 hours, or until doubled in size. Alternatively, you can let it rise in an oven that is turned off. Turn on the light only and this will speed up the rise time.
Once the dough has risen, divide it into 8 equal portions. Shape each portion into a ball, then use your fingers or thumbs to poke a hole in the center and stretch the dough to form a bagel shape.
Place the shaped bagels on a parchment-lined baking sheet. The parchment paper is important to prevent sticking.
Cover the shaped bagels with a plastic wrap again and let them rise for another 1-3 hours, or until slightly puffy to the touch. Do not over proof them. They will puff up more when they are boiled and baked in the oven.
Preheat your oven to 350°F and bring a large pot of water to a gentle boil. Add the baking soda and brown sugar to the boiling water. Carefully place the bagels, a few at a time, into the boiling water and boil for 1 minute per side.
Use the chop stick or something similar to stick into the bagel hole and spin the bagel around a few times. This helps prevent the hole from closing up all of the way. Use a slotted spoon to remove the boiled bagels and place them back on the parchment lined baking sheet. You can additionally spread cornmeal over the parchment to further prevent the bagels from sticking. They will look a little bit wrinkly. Don't worry, they will puffy up and look more smooth once they are baked in the oven.
After boiling is the time to add any special toppings, like sesame seeds, poppy seeds, cheese, bagel seasoning, etc.
Once all the bagels have been boiled, transfer the baking sheet to the preheated oven and bake for 20-25 minutes, or until the bagels are golden brown and sound hollow when tapped on the bottom.
Allow the bagels to cool on a wire rack before slicing and enjoying them with your favorite spreads or toppings.