Fill the jar halfway with sugar. Cut the beans into one to one and one-half-inch pieces and stick them into the sugar. Add more sugar to cover the beans. Close the container and place it in a cool dark closet. You may wish to wrap the jar into aluminum foil (I didnít do this but the recipe says it works better). The vanilla sugar will ready for use after 3 weeks. Add sugar to the jar as needed.
According to the recipe, the beans will release the aroma for about two years. They are still good after that, but they will need heat to release more aroma, which means they can be used for making a custard or something else where you cook them.