As we discussed below in “… a lesser of two weevils” one of the standard vignette’s in virtually any novel set in the British navy during the Age of Sail is the rapping of a ship’s biscuit on the table to draw the weevils out before eating.
Janet MacDonald, in Feeding Nelson’s Navy, notes that this may have been self-inflicted wound. She relies on a primary source for this, Captain Basil Hall experiences during the War of 1812 as recounted in Fragments of Voyages and Travels, volume 1.
Besides this capital flour, the Americans export biscuit of a delicious quality to all parts of the globe; and those only who have known the amount of discomfort produced by living on the ‘ remainder biscuit after a voyage,’ perhaps not good of its kind originally, can justly appreciate the luxury of opening a barrel of crackers from New York ! By the way, it is a curious and not unimportant fact in nautical affairs, though only discovered of late years, that the best way to keep bread for a long time perfectly fresh, is to exclude the air from it as much as possible. In former times, and even for some years after I entered the Navy, the practice was, to open the bread-room frequently, and, by means of funnels made of canvass, called windsails, to force the external air amongst the biscuit, in order, as was supposed, to keep it sweet, and to prevent decay. Nothing, it now appears, could have been devised more destructive to it; and the reason is easily explained. It is only in fine weather that this ventilating operation can be performed, at which seasons the external air is generally many degrees hotter than the atmosphere of the bread-room, which, from being low down in the ship, acquires, like a cellar, a pretty uniform temperature. The outer air, from its warmth, and from sweeping along the surface of the sea, is at all times charged with a considerable degree of vapour, the moisture of which is instantly deposited upon any body it comes in contact with, colder than the air which bears it along. Consequently, the biscuit, when exposed to these humid currents, is rendered damp, and the process of decay, instead of being retarded, is rapidly assisted by the ventilation. This ancient system of airing is now so entirely exploded, that in some ships the biscuit is placed in separate closed cases, where it is carefully packed like slates, and the covers are then caulked or sealed down. By this contrivance no more biscuit need be exposed than is absolutely necessary for the immediate consumption of the crew. If I am not mistaken, this is the general practice in American men-of- war, and it certainly ought to be adopted by us.
I remember once, when sailing in the Pacific Ocean, about a couple of hundred leagues to the south of the coast of Peru, falling in with a ship, and buying some American biscuit which had been more than a year from home. It was enclosed in a new wine puncheon, which was, of course, perfectly air-tight. When we opened it, the biscuit smelled as fresh and new as if it had been taken from the oven only the day before. Even its flavour and crispness were preserved so entire, that I thought we should never have done cranching it.