10. About 2 hours before you’d like to serve the bagels, arrange an oven rack in the center position and heat the oven to 450 degrees. Fill a large, wide Dutch oven halfway with water and place it on the stove. (Heat should be off at this point.) Set a wire rack next to the Dutch oven. If topping the bagels, spread several tablespoons each of sesame seeds, poppy seeds, caraway seeds, dried minced garlic, dried minced onion and flaky salt on separate large plates in generous, even layers. Set the plates of toppings next to the wire rack.
Tip: Mix together all the toppings to make an “everything” blend.
11. Remove one baking sheet from the refrigerator. Fill a small bowl with room temperature water, then carefully peel one ring of dough off the parchment paper and transfer it to the bowl. It should float, indicating that the bagels are ready to boil and bake. Remove the ring from the water, pat it dry on a towel and place back on the baking sheet. Remove the other baking sheet from the refrigerator.
Tip: The dough sank? That’s OK! Let both sheets sit at room temperature, covered, to finish rising, and test if the dough floats every 10 minutes after the first 30 minutes or so.
12. Set the Dutch oven over high heat and bring to a boil. Whisk in the baking soda and ¼ cup barley malt syrup. You want the water to look like strong black tea, so add more barley malt syrup by the tablespoon until it does. Bring everything back to a boil, reduce the heat if necessary to maintain a gentle boil, and skim any foam from the surface. Uncover one baking sheet and carefully transfer as many bagels as will comfortably fit in one layer to the Dutch oven, leaving some room for them to bob around. Boil for 1 minute, turning halfway through.
Tip: If the ¼ cup barley malt syrup made the liquid very dark, more like black coffee, add a little water to dilute.
13. Use a spider or slotted spoon to transfer the bagels to the wire rack and repeat with the remaining bagels on the first sheet. The bagels will swell in the water, then deflate when removed, but they will puff up again in the oven. Discard the piece of parchment that was underneath the bagels but reserve the baking sheet.