@Drunkula Haha, now this sounds like a fun (read ‘dangerous’) experiment.
Apparently “Baking soda’s chemical makeup is NaHCO3 (1 sodium, 1 hydrogen, 1 carbon, and 3 oxygen molecules). Washing soda’s chemical makeup is Na2CO3 (2 sodium, 1 carbon, and 3 oxygen molecules). When baking soda is heated up to high temperatures, it breaks down to become washing soda, water steam, and carbon dioxide.
”The process is really simple. Just heat your oven to 400 F (or 200 C), sprinkle some baking soda on a shallow pan, and bake it for about half hour, until it changes composition. You should also stir it up occasionally, just so that it bakes more evenly.”
It certainly looks more pH-ey (definitely the correct term) at 11 so I suspect I will need less of it!
<edit> It seems the advice is to rinse the boiled bagels in clean water before baking, less chance of consuming something caustic!
Apparently bagels are usually steamed/boiled before baking, pretzels are cold soaked in lye, rinsed and baked. Might have to do a split batch next time!