An early German settler, Michael Rodenkirch, wrote from “Westkonsin” to his family, who were about to emigrate in 1846, “For your sea voyage, make your own ‘Zwieback’ and take along sufficient oatmeal and wheat flour.” Zweiback means “twice-baked” to make bread dough drier, lighter, more durable, and therefore more portable. The French called their twice-baked dough biscotte and the English, “rusks.” The word “zweiback” (spelled variously, according to the degree the speller was Americanized) entered the American language late in the nineteenth century, when many German food and drink words were assimilated. In her first edition Fannie Farmer distinguishes between French rusks and “rusks,” or zweiback. The French rusk was shaped like a Parker House roll, according to Fannie, whereas the zweiback rusks were made from finger-length rolls, baked once, and then cut into thin slices and browned in the oven.

The rusks of my childhood were called “Holland Rusks,” a trade name for a package of uniform slices of crisp toast that had the reputation in my family of being “good for you.” It never occurred to me that you could make rusks or zweiback at home until I looked at “The Settlement” Cook Book and found two recipes there for an eggy-brioche dough flavored with anise, baked, and then toasted. One of these was labeled “Delicate” because the dough was made even lighter by separating yolks from whites, to make the zweiback doubly digestible and therefore “very nice for invalids.”