If the molasses jar hasn’t been opened, you can expect it to have a shelf life of at least two years as long as you are not storing it over the stove or something equally silly. Unfortunately, there isn’t total agreement on just how long molasses will last once you have opened the jar. Many say that if the molasses has been opened that it has to be used within 6 months of being opened. Some say 8 – 12 months if opened. It may also ferment if it sits around unused for very long or in warm spots. It also depends on how tight the lid is once it is opened as well.
To determine whether your molasses is still good, pay attention to its appearance and odor. It is important to look and see if there is either mold or if it has begun to crystallize. If either of those begin to happen, it may be wise to get rid of it. Also keeping it in a very warm spot can make it start to ferment and get really runny. It is wise to not keep it near the stove or oven or anywhere that is a heat source that can affect it, such as a radiator or even in front of a window. Since it is a liquid sugar substance, it will begin to crystallize if not used fast enough or left in the wrong kind of environment.
One of the ways to make it last longer before potentially going bad is to put it in the refrigerator. Although if it is too cool it can really get thick, this makes it harder to pour. If it happens to get to thick you can just sit the bottle in some warm water. It is suggested that it be kept at room temperature or even a little cooler and to keep it in a glass jar or bottle that has a lid that twist shut. Make sure that the lid is as tight as possible on the jar or bottle.
Also when storing molasses it is important to remember that air and moisture can affect the color and flavor, along with potentially causing it to crystallize faster. Don’t open it until you are ready to put it in the recipe or when you are about to use it. It is probably a good idea to not leave it sitting open waiting for someone to use it. Opening of molasses when it is not going to be used can affect the quality of the molasses. Keeping it in something that has a tight lid can really help make it keep a lot better.
Also, if you are one who doesn’t use a lot of molasses you might consider buying smaller amounts of it until you see how much of demand you have for it. There is nothing worse than getting something and having it go bad because you didn’t use it fast enough. Once you know how much you need on a regular basis it will be easier to make sure you have what you need without running out or having too much.