Quote Originally Posted by Rogar Demonblud View Post
How would they make it? Basic fermentation requires water, sugar and heat. You only have the water in the casks, no source of heat and the only sugar you get access to is the occasional issue of fruits and vegetables. Plus, sailing ships aren't exactly noted for lots of space.
Fermentation doesn't actually require any heat beyond ambient "not freezing" temperatures. You're thinking of distillation.

As for a source of sugars, you forget that starches are sugars. Ever heard of kvass? It's a kind of beer made from bread. Also, even if they do use fruits... well, they might be so bold as to steal from the ship's stocks, if they're already breaking the rules with their still.