Nice job! I’ve made bagels several times. Here’s (what I hope to be) a few helpful tips:
The diastatic malt powder is supposed to get mixed in with the dry ingredients of the dough, not the water for boiling your bagels. Although, it’s not a strictly necessary ingredient to make bagels. I think it is for flavor and helps the internal texture some.
If you don’t have barley malt syrup to add to the boiling water, you can substitute honey, molasses, or pure maple syrup. I assume you can add any kind of sugar to the water, but I haven’t personally experimented with everything.
I’ve also heard of people adding salt, baking soda, garlic, and/or onion to the water to change the flavor of the final bagels. (I think) Baking soda is also supposed to help some with chew.
If you don’t want to worry about bagel boards (or don’t know what they are), you can put a baking dish partially filled with water on a lower rack of your oven for the first five to ten minutes of baking. This will give you the steam you want to help the final crust stay softer. If your cooling rack in the picture is oven safe, you could just bake the bagels on that (a sheet of parchment paper with holes poked in it from a fork will help reduce a grid pattern forming on the bottom of your bagels) with water added to the bottom of the tray shown. Then, carefully pour out any remaining water after the 5-10 minute mark.
To be clear, you don’t need a lot of water for this. A centimeter (a bit less than 1/2 inch) deep amount is way more than enough regardless of your setup. And, please be careful with the boiling water when you remove the baking dish/pour out the extra for the final ten to fifteen minutes of baking (assuming you need twenty minutes to bake your bagels). If you end up adding to the tray and need to pour any extra water down the sink, please take the extra step to place the rack (with your bagels) on top of your stove before emptying the tray of water.
Sorry for going on about safety with boiling water. I’ve accidentally splashed some on myself before, and it hurts a LOT.
All that being said, I don’t personally think any of these steps (except safety) are set in stone as long as you, and those you share your bagels with, are enjoying the end product. So, experiment and have fun!
Also, if you’re ok with using YouTube, there is a great video by Brian Lagerstrom called “The Secret to Authentic New York Style Bagels at Home.” It’s not the only way to make bagels. But, it was my gateway into homemade bagels, and following it started me off with good results.
I just looked it up, and baking soda in the boiling water will give you closer to a pretzel outcome for the outside of your bagels. The PH change of the water helps the outside brown more.