Unveiling the Flavor of Pesto: A Guide to its Taste and Spoilage

What pesto tastes like (and how to tell if it’s gone bad)

Pesto is a popular Italian sauce known for its rich and versatile flavor. It is made with a few simple ingredients, but its flavor can be quite complex. In this article, we will explore the flavor profile of pesto, how it is made, and how to tell if it has gone bad.

Flavor profile of pesto

Pesto sauce is characterized by its peppery, creamy, and nutty flavor. The primary flavors in pesto come from the basil leaves and the crushed pine nuts. The basil leaves contribute a peppery note, while the pine nuts add a creamy and nutty texture.
Another essential component of pesto is garlic, which gives the sauce its traditional flavor. The combination of garlic, basil and pine nuts creates a unique flavor that is both savory and aromatic.
To further enhance the flavor, pesto incorporates Parmigiano-Reggiano and Pecorino Sardo cheeses. These cheeses add richness and depth to the sauce. It is important not to salt the pesto too much, as the cheeses already provide a salty flavor. A small amount of salt is enough to balance the overall flavor.
The quality of the olive oil used in pesto is critical to achieving the desired flavor. High-quality olive oil gives the sauce a grassy and smooth texture. However, store-bought pesto may not always have the same grassy notes, as some manufacturers use cheaper oils to reduce production costs.
It’s worth noting that there are several variations of pesto that use different ingredients. Pine nuts can be replaced with other nuts such as almonds, hazelnuts, or walnuts. Non-traditional pesto recipes may also include ingredients such as parsley, avocado, ginger, or coconut. The choice of ingredients will affect the flavor profile of the pesto sauce.

Texture of pesto

The texture of pesto sauce falls between smooth and too chunky. Achieving the ideal texture can be challenging, especially when using a blender or food processor. For those who prefer a perfect texture, the use of a mortar and pestle is recommended.
The thickness and creaminess of the sauce can be adjusted to taste. The ratio of nuts, basil, and liquid ingredients determines the texture. Adding more liquid, such as olive oil or lemon juice, will result in a thinner consistency. It is best to add liquid gradually to achieve the desired texture, whether thick or thin.

Uses of Pesto

While pesto is commonly used with pasta, it can enhance the flavor of many dishes. Its peppery, buttery, and salty qualities make it a versatile sauce. Here are a few ideas for using pesto:

  1. Make breakfast eggs with pesto.
  2. Bake pesto bread.
  3. Use pesto sauce as a pizza topping.
  4. Make a vegetable galette with pesto.
  5. Use pesto to top roasted vegetables.
  6. Create a pesto-crusted salmon dish.
  7. Use pesto as a sauce for chicken, steak, or pork chops.

These are just a few examples and the possibilities are endless. Pesto not only adds flavor, but also provides nutritional benefits, as it is packed with nutrients despite its calorie content.

Storage and Shelf Life

Like any sauce, pesto has a limited shelf life and will eventually go bad. The main ingredients, basil and pine nuts, are perishable and can spoil. One of the reasons pesto goes bad is because the oils in it become rancid.
Storage guidelines for pesto vary depending on whether it is homemade or store-bought, and whether the jar has been opened or not.

Store-bought pesto

If you buy pesto in a supermarket, you will usually find it in a can or jar in either the unrefrigerated or refrigerated section. If the jar is unopened, it can be stored at room temperature, away from heat sources and direct sunlight. A pantry or cool, dry kitchen cupboard is appropriate for unopened pesto that does not require refrigeration.
Once opened, the jar should be closed tightly and stored in the refrigerator when not in use. If the original container is damaged or cannot be sealed tightly, transfer the sauce to another jar or container.

Homemade Pesto

Homemade pesto should always be stored in the refrigerator. After making the sauce, transfer it to a jar or container with a tightly fitting lid. Avoid using a container that is too large, as excessive exposure to air can cause the pesto to spoil more quickly.
Unlike store-bought pesto, homemade pesto contains no preservatives and has a shorter shelf life. It is advisable to make a smaller batch if you do not plan to use a significant amount within a few days. When properly refrigerated, homemade pesto will keep for about 5 to 7 days.

Signs of spoiled pesto

It is important to know when pesto has gone bad in order to avoid consuming spoiled sauce. Here are some signs that pesto has gone bad:

  1. Change in color: Fresh pesto has a vibrant green color. If you notice that the sauce has turned brown or darkened significantly, it is a sign of spoilage.
  2. Smell: Pesto should have a fresh and aromatic smell. If you notice an unpleasant or rancid odor, it is a sign that the sauce has gone bad.
  3. Mold growth: Visible mold growth is a clear sign of spoilage. If you notice fuzzy spots or discoloration on the surface of the pesto, discard it immediately.
  4. Unusual texture: Spoiled pesto may develop a slimy or gritty texture. If the sauce feels slimy or has an unusual gritty consistency, it is best to avoid eating it.

If you notice any of these signs, the safest way to prevent foodborne illness is to discard the pesto.

Bottom line

Pesto sauce is known for its peppery, creamy, and nutty flavor profile. The combination of basil, pine nuts, garlic, and cheese creates a unique and versatile sauce that can enhance a variety of dishes. The texture of pesto falls between smooth and overly chunky, and can be adjusted to personal preference.
When storing pesto, it is important to follow proper guidelines to ensure freshness and prevent spoilage. Store-bought pesto should be refrigerated after opening, while homemade pesto should always be kept in the refrigerator. Look for signs of spoilage such as color changes, off odors, mold growth, and unusual texture.
By understanding the taste, texture, and storage of pesto, you can fully appreciate this delicious Italian sauce and enjoy it safely and flavorfully.


What does pesto taste like?

Pesto tastes peppery, creamy, and nutty. The basil leaves add a peppery note, while the crushed pine nuts add a creamy and nutty texture. Garlic and cheese add depth and richness to the flavor.

Can I use pesto in dishes other than pasta?

Absolutely! Pesto is a versatile sauce that can enhance the flavor of many dishes. It can be used as a pizza topping, in breakfast eggs, as a sauce for roasted vegetables, and even as a crust for salmon or a flavor enhancer for chicken, steak, or pork chops.

How should I store store-bought pesto?

When unopened, store-bought pesto can be stored at room temperature in a cool, dry place out of direct sunlight. Once opened, it should be tightly closed and stored in the refrigerator.

How long does homemade pesto keep?

Homemade pesto, when properly stored in the refrigerator, will keep for about 5 to 7 days. It is recommended that you make smaller batches if you don’t plan on using a significant amount within that time frame.

What are the signs of spoiled pesto?

Signs of spoiled pesto include a significant change in color, such as browning or darkening; an off or rancid odor; visible mold growth; and an unusually slimy or gritty texture. If you notice any of these signs, it is best to discard the pesto to avoid consuming tainted sauce.

Can I substitute any of the ingredients in pesto?

Yes, there are variations of pesto that use different ingredients. Pine nuts can be replaced with almonds, hazelnuts, or walnuts. Non-traditional recipes may include parsley, avocado, ginger, or coconut. Experimenting with different ingredients can create new and exciting flavors in your pesto.