Grind them into vanilla flavored sugar: This is my favorite way to deal with dry vanilla beans. As comforting as the subtle aroma of vanilla scented sugar is, it doesn’t impart much vanilla flavor. Completely dry vanilla beans are perfect for grinding with sugar for a blend that tastes as good as it smells!
Make Vanilla Simple Syrup: To rehydrate beans for use in desserts, try rehydrating them in simple syrup. Throw your dry vanilla beans into a pot with water and sugar, and simmer until the beans have softened and imparted flavor to the syrup.
For faster hydration (and stronger syrup), split the beans first. You’ll get more potent vanilla syrup and milder but more tender beans to use in your recipes.
Make Vanilla Extract: Simply steep the vanilla beans in vodka or bourbon, which will rehydrate the bean as it draws out its flavor. Not only can you still get good extract from the dry bean, but you may be able to wash it off later and use it as you would a fresh bean (assuming your recipe can tolerate a little alcohol…remember it effects freezing).
Boil Them: You can briefly boil/blanch vanilla beans to rehydrate them, however some of their flavor will leach into the water and effectively be wasted, which is why we recommend simple syrup instead.