Store-bought prepared horseradish sauce has a good shelf life when unopened, and it can be used well beyond its 'best by' date. However, it will lose its potency and may develop a bitter taste over time. If it begins to show signs of spoilage, such as mold or a strong odor, discard the jar and get a new one.
Home-grown horseradish root can last a few months in the refrigerator, but it depends on how long it was stored prior to your purchase. Fresh roots should be harvested in the fall or winter, after a frost has fallen. The cold weather will help preserve the root's pungent flavor.
When it comes to storing horseradish, freezing it is usually the best option. It can be frozen for up to a year. Although freezing it will change the texture of the root, it will not affect the pungency. To avoid a mushy consistency, it is advisable to transfer the radish into a resealable plastic bag before freezing it.
When deciding whether a jar of bottled horseradish sauce has gone bad, it's important to consider the ingredients and preservatives that are included in it. Horseradish sauce typically contains vinegar and salt, which are natural preservatives. The only time horseradish sauce should be discarded is if it shows signs of spoilage such as mold or a strong odor. A jar that is no longer thick or has become thinner and more liquidy than usual also indicates that it has gone bad.