pesto sauce

Pesto Shelf Life: Can It Go Bad?

Who doesn’t love pesto? This Italian sauce is a versatile ingredient that goes well not only with pasta, but also into your bread, sandwiches, salad, and many more!

Pesto or traditionally called pesto alla genovese originated from the Italian city of Genoa. Classic pesto is made by pounding or crushing basil leaves, pine nuts, olive oil, and parmesan cheese or pecorino cheese. If you prefer vegan pesto, more modern recipes are also available for you to try out!

Whether you make it at home or buy at the store, it’s a good idea to stock up the pesto in your kitchen. When you only have a few minutes to prepare dinner, pasta with pesto might be your go-to recipe. It’s simple yet delicious!

One time you made pesto and it’s been sitting in the fridge for a week. Do you start to wonder if the pesto is still good? The same goes for a half-full jar of pesto that has passed the “best before” date. Does pesto actually go bad? How do you know if pesto has gone bad?

If you are new to pesto or have been enjoying it for a while, this article will give you some extra knowledge about pesto shelf life, how to store pesto, and how to tell if pesto is bad. Let’s read along!


How to Store Pesto

Pesto is made from fresh ingredients and contains a good amount of oil from pine nuts and olive oil. It is safe to say that pesto is a perishable product that can go bad quickly.

Proper storage can help to reach its maximum shelf life and prevent you from wasting this delicate sauce!

If you prefer to make homemade pesto from scratch, store it in a sealed container, and always keep it refrigerated.

Similar to salsa, there are two types of pesto sauce you can find at the store; fresh pesto you can pick up at a refrigerated shelf and shelf-stable pesto (usually in a jar) at an unrefrigerated shelf.

Fresh pesto (like the one from Buitoni and Sainsbury’s) should always be kept refrigerated.

Meanwhile, a jar of pesto has been through a pasteurization process or added with preservatives.

This jar of pesto is shelf-stable and can be kept at a cool, dry place, away from sunlight and heat, such as at your kitchen pantry or cupboard. You can also keep it in the fridge, but it is unnecessary.

After opening, no matter which type, pesto needs to stay in the fridge. Similar to other general guidelines for food storage, always keep the container tightly sealed.

Hygiene practice is important to keep your food safe. Only use clean utensils to scoop the product. You don’t want to transfer any bacteria and contaminants to your pesto jar.

Can You Freeze Pesto?

Yes! The good news is that pesto freezes pretty well. Pesto producers such as Barilla and Buitoni recommend freezing pesto in a freezer-safe container to prolong its shelf life.

You can also freeze the sauce in ice cubes trays. Once frozen, wrap pesto with plastic wrap and transfer into a freezer bag or container. This way is even practical when you only need a small amount of pesto.

To unfreeze pesto, simply move it from the freezer into the fridge or put it at room temperature right before use.


How Long Does Pesto Last?

Pesto is an uncooked sauce made from fresh ingredients. Hence, the storage life is limited.

When properly stored in the fridge, homemade pesto is best to enjoy within 3 – 4 days before it loses its flavor. Consider making a portion that you can finish within those days or immediately freeze the leftover. When frozen, it can stay fresh for 2 – 4 weeks.

Ready-to-eat pesto is best consumed prior to the “best before” date on the package. After opening, fresh pesto retains its freshness in 2 – 4 days.

Meanwhile, shelf-stable pesto has a different storage period after opening depending on the producer. Make sure to check the label for appropriate instruction. For example, Barilla suggests finishing the pesto within 3 – 5 days after opening, while Fillipo Berio’s pesto is fine to keep up to 2 weeks.

Frozen pesto is best consumed for 1 – 3 months. The quality will decrease over time, so it’s always best to use it while it’s still fresh.

How to Tell If Pesto Has Gone Bad?

Your senses are quite reliable to check whether pesto is spoiled. Always inspect the look, smell, and taste.

The usual sign of spoilage is off smell. If pesto smells rotten or rancid, then it’s time to toss it.

Discoloration is also another sign that pesto is going bad. Pesto comes in light to intense green. It will oxidize slowly over time and turns from green to brownish, especially when stored for too long or exposed to air.

Before opening, make sure to check that the container is not damaged, leaked, dented.

Can You Eat Moldy Pesto?

This is a very common question whether moldy sauce, like pesto, is still safe to eat. The answer is no. Same answer if the molds grow inside the jar.

If molds grow on food with high moisture content and porous, sadly the food can’t be saved. The molds can grow beyond what we can see and thus it is considered not safe to eat the food.

Meanwhile, if molds grow on a hard or dense structure, such as on Parmesan cheese and other hard cheeses, it is more difficult for molds to penetrate. In this case, it is fine to cut ± 1 inch (2,5 cm) around and below the contaminated part and eat the rest.

If pesto still looks completely fine, try to taste a small amount to decide whether to keep it or toss it. If you’re still doubting, it is better to stay on the safe side and discard the remaining product. 


FAQs

Do you have to cook pesto from a jar?

No. You don’t need to cook or heat pesto. Pesto is an uncooked sauce and enjoyed as it is. When you make pasta dishes, instead of adding pesto to the pan over the heat, it is highly recommended to add and mix pesto on the plate.

Does pesto go bad if not refrigerated overnight?

Homemade pesto and fresh store-bought pesto should always be refrigerated, otherwise, it spoils quickly.

After opening, any type of pesto should always stay in the fridge. If left at room temperature for too long, it is risked of spoilage and for safety reasons, it should not be consumed.

Although many people may not experience health issues with food that are left unrefrigerated, it is always better to stay on the safe side. If you still decide to keep it, make sure to check signs of spoilage before putting it into your plate.

Can you eat expired pesto?

Pesto may still be edible after passing its recommended use date. Although the quality may have changed, an unopened jar of pesto may still be safe for the next 1 – 2 months when properly stored. Fresh store-bought pesto might be safe to consume up to 5 days after the use-by date.

Make sure to do a thorough check on the look, smell, and taste. If everything looks fine, try to give a tiny bit of taste to determine if you want to keep or toss it. If you are unsure if it is still fit for consumption, discard it.

Can you eat pesto with a nut allergy?

Classic pesto is made with pine nuts and sometimes mixed with walnuts. If you have a nut allergy, you should not consume pesto.

Can pesto give you botulism?

Pesto is made from fresh basil and olive oil. These ingredients are low in acids prone to Clostridium botulinum contamination from soil, water, and air (*). Homemade pesto should not be stored for too long.

Commercially-prepared pesto has undergone thorough procedures to ensure that unwanted bacteria are killed, including botulism-causing bacteria. However, it is still important to properly check a jar of pesto before opening.

If the package is damaged in any way (leaked, dented, rusted, bulged, safety button is up, etc.), there’s no safer option than to discard the product.

Summary

Pesto is a delicate sauce that goes into any pasta and other recipes. The fresh ingredients and high oil content limit pesto’s storage life. At some point, pesto will go bad.

How long pesto is good for depending on storage and the types of pesto you have. Proper storage is critical to maintain its quality and prevent spoilage. Always keep your fresh homemade pesto or an opened jar of store-bought pesto tightly sealed in the fridge.

pesto shelf life

*Photo by tycoon/depositphotos

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