This is an experimental version of my most recent recipe. I'm still tweaking it for reproducibility; some weeks are better than others. It's significantly less hobbyist-friendly than my original one, since the dough is much lower hydration.
I use some specialized ingredients and equipment, including high-gluten bread flour and barley malt syrup. For completeness' sake, I use this yeast, Diamond Crystal Kosher Salt, Grapeola grapeseed oil, literally any dark brown sugar, and Crystal Geyser Alpine Spring Water, which has a pH of 7.3. I also have a really intense mixer, a pizza stone, a kitchen scale, and bagel boards. I think you definitely need the flour, the kitchen scale, the pizza stone, and a good stand mixer such as a high-powered KitchenAid (e.g., Professional series), a Bosch, or an Ankarsrum. Alternatively, if you're really strong, you can knead the dough by hand. You have to be really strong though; I mean it. Malt syrup can be replaced by honey or molasses.
This recipe produces large, "fluffier" NY-style bagels with a lightly chewy interior, an even crumb, and a thin, crackly skin. The dough is very low hydration--less than 50%. It's a weird dough: it doesn't windowpane initially, but transforms following an hour-long rest and becomes remarkably easy to roll and shape. The presence of oil and sugar helps it last longer than other bagel recipes I've used; these bagels are still pretty decent on the second day, which is a significant accomplishment. Here are some photos.
Recipe:
First, measure out the flour, yeast, sugar, water, oil, and malt syrup, and mix until combined. (It may help to stir the dry ingredients together before adding the wet.) Add the salt and mix another 10 minutes or so; you'll know the dough is done when it's smooth, yellowish, a little sticky, and catches frequently on the spokes of the dough hook. It won't windowpane (and so it will probably tear when shaped), but it should feel stretchy and there shouldn't be any lumps.
Cover the dough and rest it about an hour; the goal here is not to achieve a rise, but to allow the gluten to relax, making shaping easier. Since the yeast is already incorporated and the dough is already kneaded, this is not really an autolyse; one thing I am experimenting with is incorporating the flour and water first, resting, then adding yeast, but I have had inconsistent results thus far. Anyway, it'll probably rise some, so punch it down and form it into a long loaf. Slice off strips and shape the bagels like this, targetting 140g bagels and arranging them on a baking sheet lightly misted with oil.
Now, allow the bagels to rest anywhere from 15 minutes to 2 hours (depending on the temperature of your kitchen), until they float when dropped into a bowl of water. In my experience, this is an important step in ensuring consistency. Proofing shaped bagels at room temperature is an important step (otherwise, your bagels won't float when boiled), and this can be done prior to or following the overnight cold ferment. However, I find that when I do it after the cold ferment, I get a lot less oven spring, and it also takes longer for the bagel to aerate enough to be boiled. So, do it before. Once you've tested a bagel and it floats, pat it dry, and put all the bagels in the fridge, covered, to rest overnight.
The next day, ideally 12 to 16 hours later, get your oven as hot as possible, soak your bagel boards, boil water, and remove the bagels from the fridge. Drop a bagel in a bowl of cool water to make sure it still floats, then add a big spoonful of malt syrup (or molasses, or honey, or whatever) to your boiling liquid. Boil bagels 10-15 seconds per side. Once they come out of the boiling liquid, arrange them face-down on the bagel boards, or, if you have a lot of bagels, drop them into a large bowl of water with some ice in it. I do not say "ice water" because I don't recommend you use a lot of ice--just some ice. The goal here is twofold: you don't want the bagels to dry out in your hot kitchen, and you also don't want them to get too hot, killing the yeast and resulting in weaker oven spring. You don't want to kill the yeast in an environment that's too cold, either, though, so... cool water, not freezing.
Once your bagels are on the boards, places boards directly on the pizza stone and allow to bake for 5 minutes. After 5 minutes, flip the boards so the bagels have direct contact with the stone and are now facing upwards. Bake another 5-10 minutes until desired doneness is reached; remove from oven, and rest bagels on cooling racks for at least 15 minutes before consuming.