Most Eighteenth Century Cookery Books contained a section on dishes that were suitable for sending off to sea with your loved one, to supplement the rations and provide some variation from the day to day fare.
This is the start of an occasional section of recipes, most of which we have tried out (although I draw the line at killing a sheep to try Sea Venison!)
Here are a two examples of items that might be taken on board to liven up the available food.
To Make Ketchup to Keep Twenty Years
(For the Captain of Ships)
Take a gallon of strong stale beer, one pound of anchovies washed from the pickle, a pun dog shallots peeled , half an ounce of mace, half and ounce of cloves, a quarter of an ounce of whole pepper, three or four large races of ginger, two ounces of mushroom flaps rubbed to pieces.
Cover all this close and let is simmer til it is half wasted, then strain it through a flannel bag. Let it stand til it is quite cold then bottle it.
You may carry this to the Indie. A spoonful of this to a pound of fresh butter melted makes a fine fish sauce.
I made this a while ago. Mine did not keep a month let alone 20 years! Maybe they did not mind removing the mould from the top before using the ketchup.