Does Salad Dressing Need to Be Refrigerated – Health and Safety Facts

Published Categorized as Journal

If you’ve ever popped open a bottle of store-bought dressing and wondered what to do with it after it was opened, you aren’t alone. The question, “Does salad dressing need to be refrigerated?” is a common one, but thankfully, it is also a question that is fairly easy to answer.

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In addition to exploring how long store-bought salad dressings can last after opening, we will also cover whether or not homemade dressings can be stored unrefrigerated, and for how long. If that sounds interesting to you, then be sure to stick around!

Table of Contents

salad dressing beside two salad bowls

How Long Can Salad Dressing Be Left Unrefrigerated?

The short answer to “how long can salad dressing be left unrefrigerated” is two hours. This is in compliance with the two-hour rule as set forth by the USDA.

However, there is a little more to it than that. 

Depending on the ingredients in your salad dressing, you may be able to get away with storing your dressing after a few hours has passed. Or even not storing it at all!

Dressings that are made with dairy or that have fresh ingredients in them, such as dressings that are homemade, will need to be refrigerated right away once used. This is especially true if the dressing you bought was refrigerated upon purchase.

If, however, the bottle of dressing you bought is sealed and was purchased at room temperature, you will only need to refrigerate that dressing once it is open. 

homemade cucumber salad

Why Does Salad Dressing Need to Be Refrigerated?

Salad dressing doesn’t always have to be refrigerated. If the dressing only contains non-perishable items – like oil and vinegar with salt and pepper, for example – then this kind of salad dressing can be stored at room temperature for a few months at best quality.

Most dressings, however, will require refrigeration of some sort. That is because most dressings contain fresh vegetables (onions, roasted peppers, and the like) or other ingredients (like dairy) that require constant refrigeration, especially once exposed to air.

As previously mentioned, bottled dressings that were purchased at room temperature can stay that way even up to a few months past the best by date printed on the label. This is provided that the bottle of dressing was never opened.

A dressing that was purchased refrigerated, however, must stay that way. These types of dressing typically do not contain many preservatives like those that were sold on the shelves. They are, therefore, more prone to spoilage. 

Does Homemade Salad Dressing Need to Be Refrigerated?

Homemade salad dressing does typically need to be refrigerated, provided that the dressing contains fresh vegetables or dairy. If the dressing only contains vinegar and oil, then refrigeration might not be necessary.

If you really aren’t sure, place your salad dressing in the fridge and use it up within a week of having made it. It is better to err on the side of safety rather than to take the risk of contracting a foodborne illness

Does Salad Dressing Need to Be Refrigerated

What Salad Dressings Do Not Need Refrigeration?

Salad dressings that do not need refrigeration include those that contain only oil, vinegar, and non-perishable spices. Some people choose to leave store bought dressings out at room temperature after opening because they know they contain preservatives. 

While it is true that dressings bought at room temperature contain preservatives to keep them fresh this way, it is also true that breaking the seal on salad dressing exposes it to air. This can lead to bacteria growth.

As such, it is imperative that you store your dressing in the fridge after opening, even if you purchased a dressing that was sitting on the shelf at the store. 

dressing salad

Is Salad Dressing OK If Left Out Overnight

Is Salad Dressing OK If Left Out Overnight?

Unless your salad dressing is a simple dressing that only contains non-perishable ingredients, you may need to throw away any opened or fresh dressings that have sat out overnight. 

As air and moisture reach your dressing, bacteria begin to form and multiply. The longer the dressing sits out, the more dangerous the dressing will be.

The reason that storing the dressing in the fridge is ideal rather than leaving it out, is because the refrigerator slows the process of decay. Therefore, placing your dressings in the refrigerator quickly after opening prevents unhealthy mold and bacteria from growing in your dressing. Refrigeration also allows the dressing to stay useable until the best by date.

Note: As always, be sure not to consume any dressing that has changed in color, taste, texture, or consistency. 

How Do You Store Salad Dressing?

The best way to store your salad dressing will depend on the type of salad dressing you have.

Use the following guidelines for each type of salad dressing: 

  • Homemade Salad Dressing: Store in an airtight container or tightly sealed glass jar for up to one week. Oil and vinegar only salad dressings may be stored in an airtight container at room temperature. 
  • Store-Bought Salad Dressing From Shelf: Store in its original container at room temperature until ready to use. Once you’ve opened the bottle, you’ll need to store this type of dressing in the refrigerator until the best buy date. 
  • Refrigerated Store-Bought Salad Dressing: Store in its original container in the fridge until ready to use. After use, you must immediately place it back in the refrigerator to keep it fresh until its best by date.

How Long Does Salad Dressing Last After Opening?

Salad dressing that has been left open will last about 2 hours before beginning to grow bacteria if it is store-bought and was purchased refrigerated. Any other opened dressings, including those that are homemade, should be refrigerated no more than a few hours after having been used.

All dressings should be thrown out if left overnight, with the exception of those made from simple and non-perishable ingredients, such as oil and vinegar. 

balsamic vinegar dressing

Does Opened Salad Dressing Need to Be Refrigerated?

Does Oil and Vinegar Dressing Need to Be Refrigerated?

Opened oil and vinegar dressings do not need to be refrigerated if those are the only two ingredients in the dressing. However, if there are any sliced vegetables in the dressing, such as diced peppers or onions, you will need to refrigerate this sort of dressing. 

Does Italian Dressing Need to Be Refrigerated?

Yes, you will need to refrigerate Italian dressing within 2 hours of having opened it. If the bottle was sold at room temperature and is unopened, it will keep at room temperature for up to a few months past its best by date. 

Newman's Own Light Italian Salad Dressing, 16-oz. (Pack of 6)

Does French Dressing Need to Be Refrigerated?

French dressing does typically need to be refrigerated once exposed to air. That said, French dressings that were bought already refrigerated should be stored in the refrigerator immediately. Keep French dressings of all types in the fridge once opened until the printed best by date. 

Annie's French Salad Dressing, Certified Organic, Vegan, Non-GMO, 8 fl oz

Does Ranch Dressing Need to Be Refrigerated?

Ranch dressing will certainly need to be refrigerated once opened because of its dairy ingredients. A bottle of ranch that isn’t open and was sold on the shelves won’t need to be refrigerated until opened. But a bottle of ranch that was purchased refrigerated must be kept refrigerated to prevent spoilage. 

Walden Farms Ranch Dressing, 12 oz. Bottle, Fresh and Delicious Salad Topping, 99% Sugar Free Low Carb Condiment, Cool and Tangy, 2 Pack

Does Balsamic Vinegar Dressing Need to Be Refrigerated?

Surprise! Balsamic vinegar does not, technically, have to be refrigerated. Like everything else, refrigeration lessens the amount of bacteria occurring in the vinegar. But generally, balsamic vinegar, on its own, will stay safe at room temperature. 

Note: Once you’ve added other ingredients to balsamic vinegar to make it into a dressing, you’ll need to store the dressing in the fridge for up to a week to preserve it. Bottled balsamic vinegars that contain a wide variety of ingredients should also be stored in the fridge once open.

Does Salad Dressing Need to Be Refrigerated? Most of the Time, Yes!

Most of the time, you will find that your salad dressings need to be refrigerated, especially once open. There are some caveats to this, however. What ingredients were used, for example? These will determine whether or not your salad dressing will remain safe for consumption if left out.

We hope that this helps! 

Learn more about salad on the blog:

By Anna

Hey, I’m Anna; writer, editor and amateur cook extraordinaire! Food has been my life and my passion for the most of my life – it’s crazy to think I didn’t pursue a career in cooking. I’m obsessed! However, keeping cooking as an obsessive hobby has worked for me – my passion grows as the years pass by – maybe I wouldn’t say the same if it was also my day job! I hope you find cooking inspiration, entertainment and “stop and think interesting tid-bits” throughout my writing – and I’d love to hear from you if you’ve got anything you want to share. Food feeds the soul – so get eating!

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