Coffee syrup should be stored at room temperature in a dry space. Once opened, the syrup will stay fresh for three to six months with the cap. If the syrup is stored with the pump dispenser, the shelf life is one to two months.  Unopened coffee syrups in plastic bottles have a shelf life of up to 24 months, while unopened syrups in glass bottles last 36 months. Unsweetened coffee syrup is made with three natural ingredients: water, sugar, and ground coffee. Once opened, unsweetened coffee syrup has a shelf life of six months. Coffee sauces have an average shelf life of one year.