With the exception of perhaps Twinkies and honey, every food in the world has a half-life. A rate at which it decays toward a slow, asymptotic, petrified or putrefied death. Sometime before it reaches that state of dryness or rot, it passes the W.E. barrier: the point at which it is no longer Worth Eating. For bagels, in particular, that line is close to zero. A good bagel will lose most of its desirable eating qualities within an hour or so of coming out of the oven, and become entirely inedible less than a day later.
But do not despair! For there are ways of casting a lifeline out to bagels that are on the brink of falling over the W.E. barrier. The question is: Which method is the best?
Let’s get one thing straight right off the bat. As a bagel sits in your kitchen over the course of a day or two, two distinct processes are going on: dehydrating and staling. In order to rescue an old bagel, you need to address both.