A thick syrup derived from sugar cane juice, molasses adds a distinctive flavor to gingerbread, baked beans, and barbecue sauce recipes. Though it's a useful ingredient to keep on hand, most home cooks find they reach for it only occasionally or rarely. Unlike honey that can last far beyond one baker's lifetime, molasses does have a shelf life. But in the right conditions, it keeps for a year or longer.
Molasses Storage Tips
Heat and humidity are the biggest threats to molasses. Both can cause bacteria to grow into mold. To avoid turning your molasses into a science project, store it in the original container, tightly closed in a cool, dry, dark place, such as the back of your pantry. Storage tips apply to all types of commercially available molasses: light, dark, and blackstrap, both sulphured and unsulphered varieties.
While it's not required, you can also store molasses in the refrigerator. But if you do, you must anticipate its use so you can pull it out of the refrigerator and let it come to room temperature first. Otherwise, it will be thick and difficult to pour. As an alternative, you can gently heat the entire jar in a pot of warm water to reduce its viscosity. Don't put it in the microwave, which can cause it to heat unevenly. Once the molasses returns to a more fluid state, you can use it as normal.
Refrigeration keeps the temperature consistent, a benefit for molasses especially in warm climates. Store unopened jars of molasses in a cool, dry, dark location for up to one year. After you open it, you can safely keep it for an additional six to 12 months in a cool location if you carefully wipe the lip of the bottle clean and securely seal the jar after each use.
Refrigeration extends storage potential to the longer end of the range.
Molasses Gone Bad
Unlike many types of hard cheese that can be salvaged when a spot of mold appears, molasses cannot be used once any mold begins to grow. If you see even a tiny spot, throw the entire jar out. Mold on molasses can look like a barely perceptible slick on the surface, or a noticeably fuzzy, discolored patch.
Molasses can also expire in less obvious ways. If it seems to have separated or has an unpleasant odor, it's also time to purchase a new bottle. At times molasses crystalizes, which also indicates that it turned. Give your molasses a little taste test before you use it again after a long period of storage; if it tastes and looks fine, it's probably still good.
But do pay attention to the best by date stamped on the jar for a time frame; the flavor of molasses degrades over time, either in an opened or unopened jar. While it may still be perfectly safe for consumption, after too much time it won't give you the high-quality results your recipe deserves.