I generally use rum extract to make a "non-alcoholic" version of my eggnog recipe (which calls for rum and bourbon). However, the rum extract in my cupboard still technically has some alcohol in it, and therefore might not always be an acceptable substitute, depending on who I'm cooking for.
What is the approximate difference in alcohol concentration when using an extract to mimic flavor, compared to the original spirit? I have always heard that the alcohol in (e.g.) rum extract is "trivial" or "insignificant," and certainly don't disagree -- but I am hoping for a more quantitative measure.