Zwieback
Scald one quart of milk and let stand until lukewarm. Add one teaspoonful of salt and one yeast cake dissolved in a little warm water, and sift in sufficient flour to make a drop batter. Beat until smooth, then cover and stand in warm water or a warm place until light and spongy. In the meantime cream together one-half of a pound of butter and one pound of sugar and beat into the mixture five eggs. Add this to the light sponge, heat thoroughly, adding sufficient flour to make of the same consistency as before, and set aside a second time to raise. When light, add flour to make a soft dough, knead and finish in all respects as for ordinary bread, but shape the loaves long and narrow and not too thick. When baked, let stand uncovered for twenty-four hours. With a sharp knife cut the loaves into half-inch slices, spread on flat pans and stand in the oven until thoroughly dry and of a pale golden color.
A rich enriched-dough loaf baked, rested a full day, sliced and dried a second time. The recipe assumes you already know how to build a sponge and finish a bread dough, so the notes below cover the quantities and the drying stage.
- Yeast cakeOne compressed yeast cake of the period is roughly equivalent to one packet (2 1/4 teaspoons) of active dry or instant yeast. Scalded milk must be cooled to about 105F before the yeast goes in.
- Weights into cupsHalf a pound of butter is 2 sticks; one pound of sugar is about 2 1/4 cups. That is a very sweet, very rich dough by modern standards, closer to a brioche than to sandwich bread.
- Flour is unmeasuredNo flour quantity is given at any of the three stages. Expect somewhere in the region of 10 to 12 cups total for a quart of milk, but add it by feel: a drop batter first, the same consistency again after the eggs, then a soft kneadable dough.
- "Stand in warm water"This means setting the bowl in a pan of warm water to keep the sponge at temperature, not adding water to the batter. A 75-80F spot in the kitchen does the same job.
- Beat into the mixture five eggsThe eggs go into the creamed butter and sugar, and that whole mixture then goes into the sponge. "Heat thoroughly" is probably a misprint for "beat thoroughly"; do not warm the dough.
- Rise timesThe book gives none. The sponge needs roughly an hour to become spongy; the enriched second rise is slower, 1 1/2 to 2 hours, and the shaped loaves another hour. Weight of butter, sugar and egg slows the yeast considerably.
- First bakeBake the long, narrow loaves at 350F until an internal temperature of about 190F, 30 to 40 minutes. A sweet dough this rich browns fast; tent with foil if it colors before it is set.
- The twenty-four-hour rest is the hingeDo not shorten it. A day of staling firms the crumb so a knife gives clean half-inch slices instead of tearing; freshly baked, this dough is far too tender to cut.
- Second bake"Stand in the oven until thoroughly dry" means a low oven, 250 to 300F, for 30 to 45 minutes, turning the slices once. They should be dry through to the center and pale gold, not browned, or the sugar will taste scorched.
- Yield and keepingEnough for three or four narrow loaves, perhaps five dozen slices. Once completely dry they keep for weeks in a tin; any remaining moisture will make them go soft and eventually moldy.
Zwieback is German for "twice-baked," the same idea that gives Italian biscotto and French biscuit their names: bread baked, cooled, sliced and dried again so that it keeps almost indefinitely. Rusks of this kind were long treated as nursery and invalid food, easy on the stomach and safe to keep in the pantry, and the sweetened, buttery German version reached American cookbooks through German immigrant households in the nineteenth century. Commercial zwieback was sold in American groceries by the early 1900s, but a cook with a good oven and a day's patience could still make a richer version at home.