I start getting ready two days before bake time by getting my starter fueled with more flour and water so that I can have 220 g of starter ready in the morning before mixing and shaping. I double my normal feeding by mixing 20 g starter, 100 g of flour, and 100 grams of water. This will rise over night and be ripe and ready at 8am.
In a large bowl, combine the warm water with the starter, then add in the malt syrup, sugar, salt and diastatic malt. Stir until you've got a smooth consistent liquid. Then add in the high protein bread flour. Mix and knead 5-10 minutes as the flour hydrates. Set in a warm (70-80°F) covered bowl to rise. Do a stretch and fold after one hour, then return to the covered bowl and continue bulk rise for two more hours.
Cut and Shape
Pull dough from bowl and cut & round 125g balls. This should give you a baker's dozen. See Mauritsio shape bagels. Shape by hand rolling and joining into a loop. Or use the 'pinch the ball' technique. Then lay onto corn meal and cover with a damp towel or other cover for final rise—another 2 hours. Then refrigerate covered until bake time. The bagels should be airy and full.
Boil & Bake
Use a large sauce pot or stock pot and boil water, at least enough to have 5 inches of water in the pot. No need to add anything more to the water. Preheat oven to 475°F. Put a steaming tray in the bottom of the oven, add lava rocks if you have them. Be sure to have tray of ice ready to add when you put the bagels into the oven. Then gently lift the bagels out of your dough trays and drop them into the boiling water. Boil on both sides for 45 seeconds to a minute. 1:30 to 2 minutes total. Lift out with a slotted spoon or ladel with holes. I let the bagels rest on a cooling rack over a cookie tray. Then as you empty the pot, add your next set of bagels into the pot. As they are boiling, you can put the bages you just pulled out on to a baking sheet or tray with parchment. Now sprinkle with sesame seeds, poppy seeds, dried garlic, salt, dried onions, and or all of the above. Then when you have a full tray, put them into the oven. And add the ice into the steam tray. And then shut the oven door and keep it shut for the first 10 minutes. This creates the steamy atmosphere that will allow the bagels to rise really well. After 10 minutes, remove the steam tray carefully and lower oven temp to 450°F. Continue to bake and rotate trays or individual bagels as needed for 5-10 minutes more, until the bagels are browing and done. Remove and place onto a cooling rack for 10 minutes to cool.