How Long Is Salad Dressing Good For After It's Been Opened?

Salad dressings often linger in the fridge long after their expiration dates — sometimes forgotten in the back of the fridge or crammed into the overstuffed door. Many people assume they're safe to use even after expiration, but that isn't the case. Once opened, salad dressings start to degrade like all foods and eventually they do expire. For your health and the quality of your go-to salad to take to the office, it's essential to track those bottles and their shelf life.

Once opened and stored in the refrigerator, the expiration of a salad dressing depends on its ingredients. Dressings made with oil, vinegar, or dairy each have a different longevity. The USDA recommends, "After opening (dressing), keep refrigerated up to 2 months," but unopened dressing is safe in the cabinet. Store-bought salad dressings often contain preservatives to extend their shelf life, but refrigeration is key to keeping the product safe for consumption once opened.

The acidity of a dressing plays a major role in how long it lasts. More acidic dressings (like Chipotle's honey vinaigrette) tend to last longer, while dairy-based dressings (like Caesar dressing) spoil more quickly. Homemade salad dressings only last a few days in the fridge due to their fresh ingredients, though vinaigrettes can stay fresh a bit longer due to the vinegar-base. Store-bought dressings, on the other hand, can remain good for over a month once refrigerated.

Whether store-bought or homemade, all salad dressing is bound to expire. Dairy-based or egg-based dressings should be consumed quickly, as they spoil the fastest. However, to extend the shelf life of store-bought salad dressings, consider transferring them to a smaller container as you use them, reducing exposure to air will help preserve its freshness for longer.

The risk of consuming expired salad dressing is primarily due to harmful pathogens, such as Salmonella and Botulinum, which can cause serious foodborne illness. However, to prevent this, look for signs that your dressing has expired. If your dressing changes in odor or texture or develops mold, it's a sign the dressing should be thrown out. If you accidentally consume rotten salad dressing and experience symptoms like vomiting, seek medical attention to diagnose and treat potential food poisoning with antibiotics or fluids. So, the next time you open your fridge, take a quick glance at those dressing bottles because some may need to be tossed in the trash.