Pesto is a popular sauce traditionally made by blending garlic, basil leaves, pine nuts, and a hard cheese (such as Parmesan) with a bit of salt and olive oil. It goes excellently with your favorite pasta dishes but more often than not, you might find that one container holds too much for one meal.
With its rather short shelf life, you probably don’t want to leave it in the fridge and forget about it. Read on for tips on how to spot if your pesto has gone bad, and how long you can store it.
Signs Your Pesto Has Gone Off
The most obvious sign your pesto is past its prime is if mold is growing on the surface or inside the container it’s being held in. This is the clearest indication it has gone bad and should be discarded immediately.
If there is not yet any mold but it smells rotten, throw it in the trash. The same goes for if there is discoloration in the basil leaves—no longer a healthy green, off pesto will turn brownish.
If you are not sure, you can always try a little bit and see if the taste is up to scratch. However, it’s best to take no risks (nobody wants the taste of off-pesto lingering on their tongue!). If you are unsure and it’s past its best-by date, the chances are your pesto has gone bad.
How Long Does Pesto Last?
If you purchased unrefrigerated pesto from a store and left it unopened, it should last for a few weeks. Remember to check the best-by date just to be certain. Once you have opened the container, its shelf life will be between seven and ten days.
If your store-bought sauce came refrigerated, it won’t last as long as unrefrigerated pesto; this is due to there being fewer preservatives in already-refrigerated pesto. Again, check the best-by date but generally, if left unopened, it should be safe for the duration of that date plus another five to seven days. After opening, be sure to finish it within five to seven days.
As satisfying as it is to make homemade pesto, the bad news is it won’t keep as long as a store-bought sauce because it’s unlikely there are any preservatives in it. You can expect it to last for about four or five days.
How To Store Pesto
Pesto in a supermarket will usually be kept in a tin or jar. If bought unrefrigerated, and for as long as it is left unopened, it can remain stored at room temperature in a cool, dark place—ideally your pantry if you have one, or a kitchen cupboard away from heat sources. Once opened, when not using, be sure to seal the lid tightly and leave it in your fridge.
If your pesto is in a tin rather than a jar, it’s best to replace it with a container that can be resealed because a tightly closed lid is what helps to keep out mold spores.
Refrigerated pesto in the supermarket should be stored at home just as you found it: in the fridge, even if unopened. Again, if it’s in a container that can’t be resealed, pour the pesto into one that can be.
Keep homemade pesto refrigerated in a jar that can be sealed tight, as it does not have a long shelf life. Want to know the best part? Drizzling a bit of olive oil on the top can help to prolong the quality slightly.
You might be wondering if you can freeze pesto: the good news is that its shelf life can be extended by storing it in the freezer! This will of course change the texture once thawed so it is recommended you freeze it in small amounts. Some recipes won’t be affected by an altered texture but some will.
This is all down to preference so it is better to test your pesto with little portions rather than freezing it all in one lump. Pouring your pesto sauce onto an ice cube tray is ideal for keeping it stored in small amounts. This way, you can defrost as much as you need and leave the rest in the freezer without wasting any!
The longest pesto that should be left frozen is thirty days but bear in mind the quality degrades over time. The bottom line is that the sooner you use up your pesto, the better—and this goes for refrigerated pesto too!