What is the shelf life of imitation vanilla extract?

Answer 1

The folks at Nielsen-Massey Vanillas (whose goal, admittedly, is to sell more and more vanilla) say you can keep properly stored vanilla extract for four or five years. Proper storage, they add, implies a tight seal and room temperature. Vanilla is expensive, but we think you can splurge more than once every 28 years, indeed, more than every 10 years. Buy a smaller bottle, if you must. And who knows, having a half-filled bottle of vanilla on your shelf that's only four or five years old may inspire you to bake a little more often. In answer to the second part of your question, read The Shelf-Life of Spices.