Hardtack

Hardtack (or hard tack) – also called ship's biscuit, sea biscuit, pilot bread, sea bread or pejoratively dog biscuit – is a simple type of cracker or biscuit, made from flour, water, and salt. Inexpensive and long-lasting, it was used during long sea voyages and military campaigns as a primary foodstuff. Hardtack was usually dunked in water, brine, coffee, or some other liquid or cooked into a skillet meal. Baked hard, it would keep for years as long as it was kept dry. For long voyages, hardtack was baked four times, rather than the more common two, and prepared six months before sailing.