In a small bowl, whisk warm water, barley malt syrup, and yeast. Let sit for 8-10 minutes to allow the yeast to activate. It is ready to use when the mixture is cloudy, aromatic, and foamy.
In the bowl of a stand mixer fitted with a dough hook attachment, add flour and salt. Stir until combined. Add all of the yeast mixture to the bowl. Mix on the lowest speed for 3 minutes. Stop mixer and let dough rest for 5 minutes.
Continue mixing for another 3 minutes on the lowest speed. At this point the dough should be stiff yet supple. Transfer dough to a clean and lightly oiled bowl. Cover with plastic wrap and let dough rest and rise at room temperature for 1 hour.
After the dough has risen, divide the dough into 8 equal pieces. I weighed mine out at 4 oz each. Form each piece into a loose ball. To form the bagels, slightly flattened the ball and poke a hole through the center using your thumb. Using both thumbs, rotate the dough and gradually stretch it to create a hole about 2 inches in diameter.
Place each formed bagel onto a greased parchment lined sheet pan. Mist the bagels with oil or cooking spray and cover with plastic wrap. Place the fridge to chill overnight.
The following morning, prepare the poaching liquid. In a large sauce pot, add the water. Make sure the water is at least 4 inches deep. Cover and bring to a boil. Once it boils, lower the heat to keep the water at a simmer and add the remaining ingredients (barley malt syrup, baking soda, and kosher salt.)
As you are waiting for the poaching liquid to come to a boil, remove the bagels from the fridge. To check if bagels are ready to be cooked, place a bagel in a bowl filled with cold water. If the bagel floats to the surface, it is ready to be boiled. If the bagel sinks, return it back to the pan and let it rest at room temperature for another 15-30 minutes. Preheat oven to 500 degrees F.
Once the bagels have passed the float test, gently lower bagels into the simmering poaching liquid using a slotted spoon. You can add as many bagels can comfortably fit in the pot. Let bagels cook for one minute, then turn each bagel over using the spoon. Let cook for another 60 seconds, then remove using slotted spoon. Place bagel, domed side up, to a lightly oiled parchment lined sheet tray. If using toppings, brush domed tops with egg white and sprinkle toppings.
Lower oven temperature to 450 ℉. Place bagels in the oven and bake for 8 minutes. Rotate pan and check the bottom of the bagels. If they are are browning too much, place another baking tray under the pan. Bake for additional 8-10 minutes until the bagels are a nice, rich golden brown. Cool on wire rack before serving.