SL - Yes I mean citrus fruit, lemon, lime, etc.
LS - Good connection on the preserved lemon, but they are super salty, I'm after something a bit fresher.
G - I have no real science except for things with a lot of citrus in them needing to be refrigerated/going bad, like sour mix etc.
The reason I ask is I make a wonderful South East Asian condiment from limes, chilis, fish sauce and sugar that goes into other dishes. I would like to bottle it and use it as a hot sauce type item, but want it to be stable enough to leave on the shelf for a few months/ship to friends, etc...