Rusk bread started as a practical necessity and evolved into a beloved treat. It was once a staple on long sea voyages, where its long shelf life provided insurance against hunger in the absence of fresh provisions. Today, rusk bread is a treasured part of many culinary traditions, a rich medium for blending textures and flavors both sweet and savory. The dry crunchy pieces are ideal for dunking in coffee, dipping in soup or arranging in casseroles to soak up sauces.

There are rusk breads from many different parts of the world. Italian biscotti are confections typically flavored with anise and almonds, though there are a world of other variations as well.

• Zwieback is a twice-baked crispy sweet bread made with egg and enjoyed throughout Europe.
  
• The Greeks have a version called paximadia, which is often made with barley flour and served with savory ingredients such as olives and feta.
  
• The Jewish mandelbrot cookie is a rusk as well. Like biscotti, mandelbrot is often made with almonds, but it can incorporate other flavors as well, including chocolate.
  
• South African rusks are also similar to biscotti, though they tend to be less sweet.

To make rusk bread from scratch, use a standard white bread recipe and replace the water with milk. If the recipe calls for an egg, use two; if it doesn't, go ahead and add one. Divide the dough into twice as many pieces as the recipe calls for so the loaves will be smaller. Once the loaves have cooled, cut them to 1/2-inch slices using a sharp knife. Bake the slices at 250F until they are a crisp, golden brown with no moisture. This may take 4 to 6 hours. Turn them over if you notice uneven browning.

You can also make rusk bread from any purchased bread that has started to go stale. It should be dry enough to easily slice into thin, even pieces, about 1/4- to 1/2-inch thick. Very stale bread, however, can be too hard to cut. Preheat the oven to 350F; place the slices on a wire rack and bake until light brown, usually about 15 minutes. Turn the slices if they are not browning evenly. For a sweet rusk, brush the slices with butter and dredge them in sugar before baking.