Bagels must be boiled in lye! No, baking soda is fine! Use honey water instead! While it is widely accepted that bagels should be boiled before being baked, regional variations have produced a range of dogmas regarding the optimal poaching solution. My favorite recipe from Serious Eats’s Stella Parks recommends only a malt-sweetened water bath, while many others use some form of arlkalinization (baking soda, or for the hardcore, lye).
Many recipes never really explain what the purpose of the alkaline solution is, but the claims include improved texture (e.g., chewiness) and browning. I’ve tried my basic recipe with both baking soda and lye, and had a sense that it also improved the flavor, but perhaps at the cost of some crispness in the crust. As far as I can tell, no one written about bagels boiled in an acidic solution.
I decided to finally do some formal testing. I prepped 8 bagels from a single batch of dough.
I prepared two pots of water with the same concentration of malt syrup (1% by weight). I added lye for a 0.5% solution (5 g per liter) to one pot and brought both to a boil. Interestingly, the alkaline solution ended up much darker.
I boiled two bagels in the malted plain water, then added 2% by volume of plain white vinegar to acidify it before boiling three more bagels. I then boiled the final three bagels in the alkaline solution. Each bagel was boiled for about 30 seconds per side. After boiling, the water and acid bagels looked pretty much indistinguishable, while the alkaline bagels were clearly darker.
The bagels went into a 425 °F oven for 25 minutes, with a rotation after 15 minutes to ensure even cooking. When they came out, the water and acid bagels again looked quite similar. I wondered if the acid bagels slightly paler, but any difference was subtle at best. The difference from the alkaline bagels, however, was markedly enhanced by baking: they were considerably darker.
I decided to sample half an acid bagel and half an alkaline bagel. When sliced, the alkaline bagel appears a bit denser, and looks smaller. I suspect the alkaline water gelatinized the proteins more quickly, and limited the rise in the oven.
The acid bagel may have been slightly crisper, but the difference was not great. I did like the more complex flavor of the alkaline bagel better. To me, it tasted more “bagely”, and less like just bread. They did indeed seem chewier.
Overall, I was surprised that the acidification little to know effect, while the difference in the alkaline bagels (compared with neutral water) was marked. It may be that I used too little vinegar to really make a difference. Regardless, I’m not sure it’s worth pursuing further since the alkaline bagels were my favorite. In addition to color and flavor, I also have the impression that alkaline-boiled bagels bind toppings better than neutral water bagels, but that’s an experiment for another day.