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How Long Does Pesto Last and How to Tell if It’s Bad?

Let’s talk about the shelf life, storage, and spoilage of pesto.

Just opened a pesto jar and wondering how long does pesto last?

Or maybe yours has been open for a couple of days already, and you need to know how to tell if pesto is bad.

Either way, you’re looking for a quick primer on store-bought or homemade pesto that will answer your pesto-related questions.

If that’s the case, you found it.

Let’s jump right in.

Fresh pesto
Fresh pesto

Table of Contents

Does Pesto Go Bad?

All types of pesto spoil sooner or later because the sauce is made from fresh, perishable ingredients that are mashed or blended together.

Store-bought pesto is usually canned, which gives it a shelf life measured in months, not days. Plus, it usually contains preservatives that help it last for more than the usual couple of days after opening.

But there are also pesto jars sold refrigerated, which come with a much shorter storage time.

Finally, there’s homemade pesto that’s free from artificial preservatives. It lasts only a couple of days before it spoils.

Knowing that, let’s talk about the shelf life of various types of pesto in more detail.

Making pesto using mortar and pestle
Making pesto using mortar and pestle

How Long Does Pesto Last?

Pesto, sold unrefrigerated, unopenedBest-by + 2 – 3 months1 week
Pesto, sold unrefrigerated, opened4 days to 2 weeks
Pesto, sold refrigerated, unopenedUse-by + 1 – 2 weeks
Pesto, sold refrigerated, opened4 – 7 days
Homemade pesto4 days

Unopened store-bought pesto keeps for a couple of months beyond its date if it’s sold unrefrigerated or for a few weeks beyond it if it’s sold refrigerated.

Once you open the jar, the sauce lasts for four days to two weeks, depending on the brand.

If those periods are not enough for you, or you simply bought a large jar instead of a small one, you can freeze leftover pesto without any issues.

(More about freezing later on.)

That’s the bird’s eye view of the shelf life of pesto. Next, let’s get into details.

Pesto Sold Unrefrigerated

Pesto sold unrefrigerated has a shelf life of about eight months to more than a year and easily keeps for a couple of months longer, as other canned products do.

After opening the jar, you get between 3 days and two weeks to use the sauce, depending on your brand of choice.

Some brands, like Filippo Berio, inform you can store their pesto for up to two weeks after opening, while others, like Mantova, go with a super short 3-day period.

Since those periods vary a lot between sellers, I suggest you read the label to ensure how long your pesto is good for after opening.

(You’re familiar with storage times being all over the place if you read my article on how long salsa lasts.)

Those differences, most likely, are caused by different amounts and types of preservatives used by various brands. So the less time you get after opening, the less “extra stuff” is in your pesto.

If you can’t find specifics on the label, use the pesto within 3 to 4 days just to be safe.

Pesto, spinach, and chicken
Pesto, spinach, and chicken

Pesto Sold Refrigerated

Sometimes pesto is sold in the refrigerated section, and that variety comes with a shorter shelf life of a couple of months tops. It also typically keeps for some time beyond the printed date, but it’s a much shorter period, like a week or two.

Once you open the jar, you usually get 4 to 7 days of storage time, depending on the ingredients used. And again, there are differences between sellers, so it’s best to check the label for more info.

Last, let’s cover how long homemade pesto is good for.

Homemade Pesto

Homemade pesto lasts about four days in a tightly closed container in the fridge. If you need more time, you can freeze the leftovers.

Pesto that you whip up at home is free of artificial preservatives, which means it lasts only 3 to 4 days, the same period all perishable leftovers do.

Some recipes might suggest you can store it for up to a week (similar to store-bought pesto), but I suggest you stick with the conservative estimate instead of risking food-borne poisoning.

(All the above is also true for other homemade sauces – homemade hummus lasts about 4 days as well.)

Knowing that, let’s talk about how to tell when your pesto is spoiled.

Pasta, pesto, and spinach
Pasta, pesto, and spinach

How to Tell if Pesto Is Bad?

Discard pesto if:

  • Its color has changed. If your pesto that’s usually green (there are other flavors, too) has turned completely brown, that’s no good.
  • There’s mold on the surface. Any fuzzy action on the surface means it’s game over for the sauce.
  • It smells or tastes rancid. If the sauce gives off a bitter, putrid, or chemical smell, or tastes harsh and bitter, it’s time for it to go. An unopened jar of pesto that’s stored for too long in bad conditions can go rancid because that’s how old olive oil spoils and pine nuts go bad. Eating rancid pesto most likely won’t make you sick, but it won’t taste nearly as good as fresh pesto.
  • It sits in storage for too long. If the jar says you should use it within seven days, and it’s sitting in the fridge for two weeks already, it’s time for it to go. The same is true with homemade pesto that’s refrigerated for a week or so. When it comes to unopened pesto, it’s difficult to give specifics, so you must go with your gut.

Finally, if you notice any other suspicious changes, toss the pesto. Better safe than sorry.

Next, let’s talk about how you should store pesto.

Fresh basil
Fresh basil, needed for fresh pesto

Does Pesto Need to Be Refrigerated?

All open pesto jars require refrigeration.

The only time you don’t have to store pesto in the fridge is if what you have is an unopened jar of store-bought pesto that wasn’t refrigerated in the supermarket. Once you open that jar for the first time, it goes into the fridge.

Every other variety, including homemade pesto, must sit in the refrigerator at all times.

Having that out of the way, let’s talk about other storage practices.

Other Storage Practices

Make sure your pesto jar is always sealed tight when not in use and that you’re using clean spoons when scooping. Double dipping is not an option.

To prevent pesto from browning, pour a thin layer of olive oil on top before you place the jar back in storage. Alternatively, you can cover the surface with plastic wrap to get the same effect.

Both work because they create a barrier between the pesto and fresh air, preventing it from enzymic browning caused by oxidation.

Similar tricks work if you want to prevent guacamole from browning – just use water instead of oil.

Pasta with pesto and spinach
Pasta with pesto and spinach

Can You Freeze Pesto?

Yes, you can freeze pesto to extend its shelf life, and it works well for both homemade and store-bought pesto. All you need is a plastic container and a minute or two.

To freeze pesto, spoon the sauce into an airtight container, leaving a few inches of space before closing the lid.

Keep the airtight lid secure so that the sauce won’t leak out. And add a label with the name and storage date if you like, then stick it in the freezer.

Pack the sauce into manageable portions so you don’t have to defrost the entire container for a single serving of pesto. If you don’t have as many containers as you need, or use only a small amount of pesto at a time, freeze it in ice cube trays.

When kept in the freezer, store-bought pesto sauce will retain the best quality for about 8 months or so. The homemade variety usually doesn’t keep as well, so it’s best to finish it within like 6 months.

If you want to learn more about the topic, I wrote a whole guide on freezing pesto on my sister site

Pesto Shelf Life and Spoilage Summary

Thanks for reading this primer on pesto. Here are the takeaways:

  • Store-bought pesto easily lasts beyond the printed date, and it keeps for four days up to 2 weeks after opening, depending on the brand.
  • Discard pesto that’s changed color, grows mold, or smells or tastes rancid. Do the same if it sits in storage way past what’s reasonable.
  • You can store an unopened jar of shelf-stable pesto in the pantry or any other cool and dark place. Once you open it up, it requires refrigeration, and so does every other type of pesto, including homemade.