There are many things to do with old bread. If it's not too hard, you can thin slice it and bake it with a little fat (olive oil, butter, lard...) to make crackers, or cube it up for croutons. You could even toast and crush it into bread crumbs, I suppose, if you didn't mind the unholy racket of your food processor. Or you can practice the peasant trick of adding leftover bread to soup, as with Italian ribollita. The last is especially nice in this wet, soupy season.
But the most interesting of all the old-bread repurposings, I think, is to re-ferment it into a drink. Kvass, or kwas, or квас, is a slavic soda made from old bread. Actually, after digging deeper into the astonishing, meandering mind of Sandor Katz, I learned that kvass can refer more generally to northern European low-alcohol fermented drinks, like the beet kvass you might use for borscht, or lettuce kvass, which was once a common summer drink among my Ukrainian ancestors, before the shtetls were exterminated by the Holocaust (I'll admit, I'm skeptical of the deliciousness of lettuce soda, but am willing to try this summer when greens are abundant).
I am far from a kvass expert, but if you'd like to try this strange and lovely drink for yourself, the general idea is simple:
On the new bread front, I'm baking Red & White, Mountain Rye, and Wild & Seedy this week. Order HERE by 10 am tomorrow for Wednesday pickup.