How Long Does Ranch Dressing Stay Good For After Opening?

Stay in the U.S. Midwest for any period of time, and you'll see people use ranch dressing with literally everything, from pizza and wings to pasta salads, chicken fingers and fries, and even tacos. They love their ranch (it's most popular in North Dakota and Minnesota), and they love discussing which ranch is best. Whether you live in the Midwest or you're just channeling those Heartland vibes from another part of the country, an open bottle of ranch dressing is a staple in many household refrigerators, but how long does it keep?

While the USDA website says that salad dressing is good for up to two months in the fridge, some push the fresh-and-edible period to six or even nine months. It's dependent, of course, on how it's stored in the fridge, as well as which brands and what types of preservatives they use in the recipe (and certainly, store-bought dressing, such as we're discussing here, lasts longer than homemade — like this cilantro ranch recipe – which has none of the preservatives added to the former).

Ranch, being made up primarily of the dairy items buttermilk and sometimes sour cream, should definitely be kept in the fridge after opening. Your first instinct may be to store it in the refrigerator door, but due to its highly perishable nature, it's better to keep it on a lower shelf, toward the back, where it's coldest. This way it won't be as subject to temperature fluctuations every time you open the door. If by some chance the lid to your ranch dressing breaks, you should place it in another airtight container, as leaving it open in the fridge can expose it to bacteria from other food items.

Unopened bottles of ranch dressing can be stored at room temperature, in the pantry, but if you open it and leave it out on the counter for longer than two hours, it's probably a good idea to toss the entire bottle. This is because perishables left out for two hours or more enter what the USDA calls "the danger zone," where bacterial growth is much more likely.

You can do everything right and still your ranch may go bad before its one to two months are up. One sign that it's turned is the smell. Right away, when you open the bottle, if you smell anything rancid or sour, you should not put it on your food and should instead toss it in the garbage (better safe than sorry!).

Another sign is its color; ranch dressing has a typically white base, so if it's turned to another color — yellow, brown, or even green — that is not something you want to be ingesting into your body. Some of the time, the ranch has turned a different color due to the presence of mold. Mold in your ranch dressing is a red alert situation; throw it out immediately. Also, while your ranch might separate without having gone bad (you can just shake the bottle to reconstitute it), the appearance of separation, plus any of the other signs, means the bottle is no good anymore.