Add water and sugar to a medium sized saucepan over medium high heat. Bring to a boil, stirring until sugar has dissolved.
Add the vanilla bean and cook for 2 minutes more, then remove from the heat. Allow the syrup to cool for at least 1 hour with the vanilla bean steeping in the syrup.
Remove the vanilla bean from the saucepan and discard. (If there are any large bits from the vanilla bean, you can strain the simple syrup through a fine mesh sieve or cheese cloth.)
Use immediately or transfer to a clean glass jar with a lid for storage. Store vanilla simple syrup in jar, tightly sealed, in the fridge for up to a month.
Storage: Store the vanilla simple syrup in a clean, dry glass jar with a clean, dry, tight-fitting lid. Moisture can cause syrup to spoil. Refrigerate for up to 1 month, or freeze for up to 1 year.Spoilage: Cloudy or bad-smelling vanilla syrup is spoiled and should be discarded.