Hardtack (or hard tack) is a simple type of biscuit or cracker, made from flour, water, and sometimes salt. Hardtack is inexpensive and long-lasting. It is used for sustenance in the absence of perishable foods, commonly during long sea voyages, land migrations, and military campaigns.
== Etymology ==
The name is derived from "tack", the British sailor slang for food. It is known by other names such as brewis (possibly a cognate with "brose"), cabin bread, pilot bread, sea biscuit, "soda crackers", sea bread (as rations for sailors), ship's biscuit, or pejoratively as "dog biscuits", "mol...