Bagels are usually dipped in lye as well, it's how they get their bagel-y texture on the outside crust. Sodium carbonate is sometimes used as an alternative to

Bagels are usually dipped in lye as well, it's how they get their bagel-y texture on the outside crust. Sodium carbonate is sometimes used as an alternative to lye for those who don't want to deal with the safety aspect of handling lye, as lye is very caustic. Of course, lye still provides the best results.