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Can Salad Dressing Go Bad?

If a homemade salad is part and parcel of your dinners, that’s great. And you definitely know that the dressing is in many cases what makes that salad great. Because of that, we often buy multiple bottles of different brands, test out various dry mixes, and try different recipes we find online. All of that to find the perfect dressing for your favorite salad or a few ones to choose from depending on your mood or the ingredients of the salad.

And if you’re still in the trenches, searching for the holy grail, you probably have a few half-open bottles, and possibly a host of dry mixes stashed. Sooner or later, you start wondering: can salad dressing go bad?

Or perhaps you’re not that into salads, and it takes you a few months to clear a single bottle of ranch or Italian dressing. Nothing wrong with that. But now you’re wondering how to tell if that dressing that’s sitting in your fridge for quite some time is bad or not.

Vegetable salad
(credit: Jasmin Schreiber )

Either way, this article is all about salad dressings. I divided it into three sections, one for each type: bottled, dry mix, and homemade. Each one is a different beast entirely, so it makes perfect sense to make that division. If you’re looking to learn a bit about dressings, read on.

Store-bought Bottled Dressings

These are probably the most popular ones out there, for the same reasons pesto, ketchup, or mayonnaise are. They are super-convenient, especially if you’re whipping up a salad in a hurry. Please note that the guidelines I provide are pretty generic, as there are dozens of dressing styles available. Plus various producers add different amounts of preservatives to their product. So listing specifics for everything available is neither possible nor makes sense. I believe that a few basic rules go a long way here.

Can Bottled Salad Dressings Go Bad? How To Tell If One Is Bad?

Sure they can. While they’re often quite high in preservatives, they still spoil if you store them long enough or in adverse conditions. Signs of spoilage are pretty typical: mold, off or rancid smell, noticeable change of texture or taste. If either one is present, throw out the bottle.

One exception here: oil-based dressings, like Italian, separate naturally, so some separation is expected and shouldn’t concern you. Just shake the bottle before using to make it more even, and you’re good to go. If it’s not an oil-based dressing and it separates, throw it out for quality reasons.

How Long Does Bottle Salad Dressing Last? How To Store It?

Bottled salad dressings come in two different types. Most of them are sold unrefrigerated, but every now and then you can find one that’s in the refrigerated section in the supermarket. And different rules apply to both.

When it comes to dressings sold refrigerated, these you should always keep in the fridge. Their shelf life isn’t that long, usually up to a few weeks. They come with a use-by date that’s a pretty good indicator of how long they retain good quality. Of course, you often can use such a dressing for a few days or even a week past that date, depending on when you open it. As usual, the longer it’s opened, the worse the quality and bigger chance it spoils.

Bottled dressings sold unrefrigerated can be stored at room temperature until you open them. That means a pantry or a cabinet in the kitchen works perfectly. Just make sure the bottle is not near any heat sources or in direct sunlight. Once you open the bottle, make sure it sits in the fridge when not in use.

Salads and dressings
(credit: Taylor Kiser )

When it comes to shelf life, it’s usually a minimum of a few months. Again, there’s a best-by date on the label to help with that. And as you might imagine, the dressing often lasts even for a month past that date if it stays unopened.

After opening, bottled dressings usually last between 3 to 6 months, but make sure to check the label of yours, as those periods vary depending on brands and styles. If you expect to have it opened for longer than a few weeks, it might be a good idea to write the date of opening on the label. And if it already sits for quite some time, check it for signs of spoilage before using.

Dry Mix Salad Dressings

Dry mixes are a great choice if you need some help with making a salad dressing every now and then. And they are spice mixes for the most part, so you deal with those pretty much the same way you deal with spices. That means you should store the packets at room temperature in a dry place. If you don’t use the whole thing in one go, make sure to seal it as tightly as possible, or even transfer the leftover dust to a resealable bag.

When it comes to shelf life, it’s usually between a year and two years, and you should be able to get away with using the mix with excellent results even after a few months past the date on the label. Worse thing that’s like to happen is that the mixed dressing won’t taste quite as flavorful as it usually does. That’s because some of the spices from the mix have probably lost of their potency.

Generally, as long as moisture doesn’t get to the powder, it should be safe to use. But if it’s already more than a few months past its date, it’s probably better to get rid of it regardless.

Two bolws of salad and salad dressing
(credit: Travis Yewell )

Homemade Salad Dressings

Like with bottled dressings, there are far too many recipes and styles available to cover all of them in detail. So instead I came up with a few basic guidelines you can apply to any dressing you prepared for your Caesar (or any other, for that matter) salad.

When it comes to storage, it’s plain and simple: keep the leftover dressing refrigerated and sealed tightly. You can use a plastic bottle, a glass jar, a resealable container, or whatever else gets the job done. The spoilage signs are pretty much the same as for bottled dressings. The only thing to remember is that because you’re not adding any preservatives to your homemade dressings, it spoils quickly. So be even more careful with checking if the mixed ingredients are still fit for use.

Last but not least, let’s talk shelf life, as you’re probably wondering how long does your homemade salad dressing last. Unfortunately, there isn’t a one-size-fits-all answer, but I have some tips. If you’re whipping up a dressing using ingredients that last long on their own, the dressing can usually last in alright quality for about a week, and sometimes even longer.

A vinaigrette is a good example, as both olive oil and vinegar last a long time, and additional ingredients such as maple syrup or mustard also keep really well. If, on the other hand, it’s a dairy-based dressing like ranch, it definitely won’t last as long, and 3 to 4 days of good quality is all you can hope for in most cases. Also, many dressing recipes mention how long the mix keeps, so search for that piece of information if you expect leftovers.

In a Nutshell

  • to check if your salad dressing isn’t spoiled, make sure it’s not moldy, smells alright, and its consistency and taste haven’t changed; except for oil-based dressings, they tend to separate, and that doesn’t make them unsafe to eat
  • for bottled salad dressings, observe the date on the label; if it’s a dressing sold refrigerated, it won’t last much past its date; dressings sold unrefrigerated last unopened up to a month past their date, and usually a few months after opening; check the label of yours for details
  • dry mixes last months, as long as water doesn’t get to the powder, they should remain okay to use; worst case scenario the dressing won’t taste that good, in which case you should discard it and use a newer one
  • homemade salad dressings should be always refrigerated and usually last between 3 days up to a week, depending on the ingredients; check the recipe for specifics