Chocolate and war

Chocolate's physical properties suit a soldier's pocket unusually well: high energy per unit weight, no preparation, no refrigeration in temperate conditions, and a long shelf life if kept dry. Armies noticed early, and by the twentieth century chocolate was standard in emergency and field rations across several combatant nations.

Military requirements produced formulations unlike anything on sale. Ration chocolate had to survive heat without slumping and had to resist being eaten casually — a bar meant to sustain a soldier for a day is defeated if it is treated as a snack — so it was made deliberately dense, hard and comparatively unpalatable, with formulations adjusted for tropical service. Some of that work fed back into commercial heat-resistance research afterwards.

At home the same qualities made it scarce. Shipping space, foreign exchange and raw-material supply all constrained cacao imports, and chocolate and sweets were rationed in Britain during and long after the Second World War, with rationing continuing for years after the fighting stopped.

The cultural residue outlasted both. Chocolate acquired an association with comfort, scarcity and treat status that is still visible in how it is marketed and given, and for a generation the return of unrationed sweets was a dateable, memorable event.