Don’t add baking soda (glad it wasn’t lye) to already boiling water that also has some barley malt dissolved!
Mine literally exploded and spewed foamy water all over cooktop, floors, and into drawers. I was torn between trying to clean it up and also trying to dunk the pretzels. I probably didn’t have enough soda in the water as pretzels baked brown mostly from the egg wash and not the alkali.
Fortunately baking soda, esp. mixed with water, puts out fires, so no flames when all that liquid hit the burners.