Below is a generalization using extracts which usually have 35% alcohol base. I use the sniff/smell option.

Extract Shelf Life
Pantry
Extracts Indefinitely
Handling Tips:
Keep tightly closed; volatile oils escape.
Extracts will generally last (maintain quality) indefinitely until they evaporate. But, if you doubt that, sniff and, if you wish, taste. If the scent and taste are good, they will do their job in your recipe. If there's no aroma, discard.
Source(s):
Spice House, Evanston, IL