Combine the water, yeast, and sugar in a small bowl. Mix and let it sit for 3-5 minutes.
Add this mixture with the flour and salt to a mixer (you can also knead this by hand). Mix it on medium speed for 8-10 minutes.
Cover and let this rest for 40 minutes at room temperature.
Preheat oven to 425 degrees. Line another baking sheet with parchment paper and sprinkle with cornmeal.
Bring the 10 cups of water to boil in a large pot.
Divide the dough into 12 equal pieces. Roll each piece into a ball. Let the balls rest for 5-10 minutes. With your thumb. Gently stretch the bagels with both thumbs.
Add a few of the bagels at a time. Cook them for 45 seconds on each side. Remove with a slotted spoon and place on the prepared pan.
Once they are done, combine the egg and milk. Brush each bagel with the egg wash and sprinkle with whatever toppings you are using.
Place in the oven and bake for 15-22 minutes. They should be a deep golden brown color.
Remove from the oven. Allow them to cool for about 5 minutes on the pan. Then gently remove them and place them on a cooling rack.