Your refrigerator shelf might have many open condiments taking up fridge space, so it's good to check your sauces every now and again to be sure that they are still fresh. There are three main ways to check a food's quality: its look, scent, and expiration date, but this is one definite sign that you should get rid of some of those open jars.

Look for any water or liquid at the top of the jar — if you see any liquid (especially if it's paired with discoloration), then that condiment is long past its shelf life. One big way to keep condiments fresh for as long as possible is to use a specific knife, spoon, etc., for that condiment and nothing more, which will help limit how much bacteria get into the jar in the first place.

The shelf-life of a condiment changes depending on what it is, but the best way to keep track of its' freshness is to have a basic understanding of how long it lasts. According to the USDA, mustard stays fresh for up to one year, horseradish withstands four months, mayonnaise only lasts about two months, and ketchup, cocktail sauce, and chili sauce keep for about six months.