Finest Call Premium Pure Cane Sugar Simple Syrup Mix, 1 Liter Bottle (33.8 Fl Oz) In Single Box

Q: Should the cane sugar simple syrup be refrigerated after opening? and how long is it good after opening?

My purchase was less than two weeks ago, so no opinion yet on longivity. NO WHERE on the label or container is there any notice to "Refrigerate After Opening". Undoubtedly there is a perservative added because my home made syrup grew mold when not refrigerated.