Simple syrup generally lasts about 1 month in the fridge if homemade with a 1:1 sugar to water ratio. Rich simple syrup (2:1 sugar to water) can last up to 6 months refrigerated. If infused with herbs, spices, or fruit, the shelf life reduces to about 1–3 weeks depending on the ingredients. Store it in an airtight container in the refrigerator to maximize freshness. Unrefrigerated syrup can spoil in about a week. Store-bought syrups with preservatives can last longer, up to 6 months or more unopened at room temperature and 2 months refrigerated once opened. Simple syrup can also be frozen for up to a year.