I’ve been reading Shōgun, and one scene addressed the issue of scurvy, saying a limiting factor on voyage duration was the amount of fresh fruit a ship could keep good.. and that extracts/tinctures/etc went rancid after a few months. I read the Kingsbridge Trilogy last week, and it seemed like everyone used sour apples to make cider. What I’m wondering is, why didn’t sailors just drink cider instead of grog, or in addition to it, since it seems like as it’s made from apples, cider should prevent scurvy? Or is the concentration of nutrients diminished in the fermentation process (for hard cider)?
Edit: Well, I answered my own question... or rather, the ship’s physician (James Lind) of the HMS Salisbury answered it for me.
“After the oranges, Lind observed that apple cider had the most beneficial effect on the seamen. Although the sailors on apple cider were not well enough to work, their gums improved somewhat, their weakness abated slightly and their appetites improved. Apple cider has a tiny amount of vitamin C, which caused moderate improvements in the men's health, but not enough to cure the disease.”
I've actually written about scurvy before, as well as why the British navy drank the types of alcohol they did, here and here, if it's of help. But the basics are that while it was fairly well known that fresh food would prevent or ameliorate symptoms of scurvy, the connection between vitamin C specifically and scurvy was not made until much later than the time period in Shogun, which if memory serves is early- to mid-17th century; and spirits of whatever type store much smaller than beer. I'm not totally sure what the "rum ration" would actually have been in the Portuguese navy of this period, other than it wouldn't have been rum, but perhaps someone such as /u/terminus-trantor would be able to provide some information on this.