In a large bowl, combine the sponge ingredients, mixing until fully combined. Cover the bowl with plastic wrap and let sit at room temperature for 2 hours. The sponge will be fluffy and bubbly.
Add all the dough ingredients into the sponge and knead until combined. I do this for a few minutes in the bowl and then transfer the dough to your counter to continue kneading. Knead until the dough is smooth and very stiff. If your dough is sticky, gradually add a bit more flour. You can also do this step in a stand mixer using a dough hook.
Line 2 baking sheets with parchment paper and set aside. Divide the dough into 12 portions and roll each portion into a smooth ball. Place 6 balls on each prepared baking sheets and loosely cover with plastic wrap. Let the trays rest on the counter for 20 minutes.
Gently poke your finger through the center of each ball, making a circular motion to form the hole. I then use both of my pointer fingers (one on either side) to gently stretch the hole using a circular motion (picture fidgeting with a rubber band). Place the bagels back on the 2 baking sheets and loosely cover with plastic wrap. Let rest on the counter for 20 minutes and then transfer the trays to the refrigerator. Let rest in the refrigerator for 3 hours or overnight. I prefer overnight if you have the time (this allows for better structure and flavor).
Boiling & Baking
Remove the trays from the refrigerator. Preheat the oven to 500 degrees. Bring a large pot of water to a boil. While the water is coming to a boil, let's get everything prepared. You'll need a baking sheet lined with a dish towel or paper towels, a large slotted spoon or spatula, and dishes with all your toppings laid out. For toppings, you'll want these to be wide enough that you can fit the bagel into the dish. Add the baking soda to the boiling water. This enhances the color and flavor!
This next part moves quickly! Gently place 3 bagels into the boiling water for 30 seconds. Use the slotted spoon to flip the bagels over and boil for another 30 seconds. Promptly remove from the water and immediately place into the toppings. The timing here is key--if you wait, the toppings won't stick. After the toppings, move the bagels to the towel lined baking sheet. Repeat until all the bagels are boiled and topped.
Line a baking sheet with parchment paper and move the bagels onto the baking sheet. It's fine if they touch. Place the tray into the preheated oven and immediately decrease the temperature to 450 degrees. Bake for 10 minutes, rotate the pan if baking unevenly and continue baking for 10 - 15 minutes until the bagels are a deep golden brown. Remove from the oven and transfer to a cooling rack to cool for 10 minutes and then dive in!
Authentic NY Style Bagels https://500spatulas.com/authentic-ny-style-bagels/