@205381b6 Related to the chestnut, maybe?

As noted previously, pretty sure you could use them for a tea or coffee(?!), but these days the processing was just intensive enough to not be worth it. Can't find it, but seem to recall chicory and the like replacing it, since they didn't require the same work to make potable (depending on your opinions regarding "coffee substitutes".)

Might look through archive.org or Google Books for old recipes books, might be something for a cake/cookie/pie?