How to know if basil is spoiled? (6 easy ways)

In this brief article, we are going to answer the question “How to know if the basil is spoiled”, discuss the different methods of identifying the spoiled basil and the potential side effects of eating spoiled basil.

How to know if basil is spoiled?

When basil is spoiled, there are several signs you can look out for to determine its freshness. Here you can find the six more common signs of basil spoilage:

Important: consuming spoiled basil is strongly discouraged due to the presence of harmful microorganisms and their toxins, which can potentially cause severe illness (1-5).

  1. Discoloration: fresh basil leaves have a distinct vibrant green color. If you are observing that the color of your basil is turned into brown or black, then it gives you a strong sign that the basil is spoiled.
  1. Slimy texture: healthy basil leaves should be dry and crisp. If you are observing some moisture contents on the surface of the basil, then this tells you that the basil is spoiled. 

When basil leaves become slimy or develop a wet, mushy texture, it indicates bacterial growth and decay. As a precaution, it is commonly advised to keep the basil in a dry and cool place otherwise it will spoil quickly.

  1. Wilting: if the leaves of your basil appear limp, wilted, or droopy, it indicates that the basil is no longer fresh and has surpassed its prime state.
  1. Mold or fungus: when examining basil leaves, check for any indications of mold or fungal growth. Mold may manifest as fuzzy patches or dark spots on the leaves. 

If you detect any presence of mold, it is crucial to discard the basil right away, as consuming it can pose health risks (6).

  1. Off smell: the aroma of fresh basil is typically delightful and fragrant. However, if you detect a foul or musty odor coming from the basil, it is a clear indication of spoilage. 

Trust your sense of smell, and if the basil emits an unpleasant or off odor, it is advisable to discard it.

  1. Yellowing or darkening stems: when inspecting a bunch of basil, pay attention to the stems. If the stems have changed color to yellow or dark tones, it indicates that the basil is spoiled. 

Remember that healthy basil stems should have a vibrant green color and exhibit a sturdy texture.

It is important to prioritize caution and dispose of basil that displays signs of spoilage.

Consuming spoiled basil can result in gastrointestinal problems and other potential health issues (1-5). Thus, it is always better to be safe and discard any basil that raises concerns about its freshness or quality.

Can you get sick from eating spoiled basil?

Yes, eating spoiled basil will increase the possibility of getting serious diseases due to the presence of harmful microorganisms, viruses, parasites, and toxins (1-5).

Here you have a summary of the most common risks:

  • Bacterial infections: spoiled basil can harbor different pathogenic bacteria such as Salmonella, pathogenic Escherichia coli, Listeria monocytogenes, or Campylobacter (3-5). 

These bacteria can cause food poisoning and lead to symptoms such as nausea, vomiting, diarrhea (which may be bloody), abdominal pain, fever, and in severe cases, dehydration.

  • Mold-related health issues: mold growth on spoiled basil can produce toxins such as aflatoxin, which is produced by certain strains of the fungi Aspergillus (7). 

Consuming basil contaminated with aflatoxin can result in symptoms like liver damage, nausea, abdominal pain, and potentially long-term health problems.

  • Viral infections: although less frequent, it is still possible to get a viral infection from spoiled basil. For instance, norovirus, a highly contagious virus, can survive on contaminated surfaces, and reach your basil (8). 

Basil contaminated with norovirus can lead to symptoms such as nausea, vomiting, diarrhea, stomach cramps, fever, and body aches (8).

  • Parasitic infections: Parasites like Cryptosporidium, Giardia, or Toxoplasma gondii can also contaminate your basil. These parasites can cause gastrointestinal symptoms like diarrhea, abdominal pain, and nausea (1). 

In specific situations, these parasites can pose significant risks, especially for individuals with weakened immune systems, who may be more susceptible to severe complications.

It is important to highlight that the specific risks can vary depending on the type of pathogen that is present on your spoiled basil.

If you suspect that you have consumed spoiled basil and experience any of the above-mentioned symptoms, it is very recommended to seek medical attention immediately.

What should you do if you suspect you have eaten spoiled basil?

If you have consumed spoiled basil and suspect food poisoning or adverse effects, here you can find three important recommendations:

  1. Monitor your symptoms: it is important to closely monitor your condition for any potential symptoms that may arise, including nausea, vomiting, diarrhea, stomach cramps, fever, or indications of gastrointestinal discomfort. 

Take note of the severity and duration of these symptoms for better assessment and communication with healthcare professionals, if necessary.

  1. Stay hydrated: in case of vomiting or diarrhea, it is essential to maintain proper hydration by consuming sufficient fluids. 

Choose water, electrolyte solutions, or clear broths as preferable options to replenish lost fluids and prevent dehydration.

  1. Seek medical advice: in case of severe, persistent symptoms, you should seek medical attention immediately. 

Remember that it is important to contact your healthcare provider or local emergency services for guidance and advice regarding your specific situation.

How to properly handle basil to avoid spoilage?

To handle basil properly and extend its shelf life, consider the following tips for short or long-term storage:

  • For short-term storage (up to a week) you should keep your basil at room temperature. 

It is recommended that you wrap your basil loosely in a damp paper towel, then place it in a plastic bag and store it in the refrigerator.

  • For long-term storage (up to several months): you should first plunge your basil in boiling water for a few seconds and directly transfer it to an ice bath to stop the cooking process. 

After blanching and flash freezing the basil leaves, transfer them to an airtight container or freezer bag, ensuring to eliminate as much air as possible before sealing. Then, you can place the container or bag directly in the freezer for storage.

The shelf life of basil can vary depending on the freshness and storage conditions (9). 

Generally, fresh basil can last for about 3 to 7 days when stored properly in the refrigerator. Frozen basil can retain its quality for up to 3 to 6 months.

Remember to inspect the basil before using it and discard it if it shows signs of spoilage.


In this brief article, we answered the question “How to know if the basil is spoiled”, and discussed the different methods of identifying the spoiled basil and the potential side effects of eating spoiled basil.


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2. Li D, Uyttendaele M. Potential of Human Norovirus Surrogates and Salmonella enterica Contamination of Pre-harvest Basil (Ocimum basilicum) via Leaf Surface and Plant Substrate. Front Microbiol [Internet]. 2018 Mar 29 [cited 2023 May 17];9:1728. Available from: 

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6. Pleadin J, Frece J, Markov K. Mycotoxins in food and feed. In: Advances in Food and Nutrition Research [Internet]. Academic Press Inc.; 2019 [cited 2020 Apr 27]. p. 297–345. Available from: 

7. Umesha S, Manukumar HM gowda, Chandrasekhar B, Shivakumara P, Shiva Kumar J, Raghava S, et al. Aflatoxins and food pathogens: impact of biologically active aflatoxins and their control strategies. J Sci Food Agric [Internet]. 2017 Apr 1 [cited 2023 May 17];97(6):1698–707. Available from: 

8. Rönnqvist M, Aho E, Mikkelä A, Ranta J, Tuominen P, Rättö M, et al. Norovirus transmission between hands, gloves, utensils, and fresh produce during simulated food handling. Appl Environ Microbiol [Internet]. 2014 [cited 2023 May 17];80(17):5403–10. Available from: 

9. Lange DD, Cameron AC. Postharvest Shelf Life of Sweet Basil (Ocimum basilicum). HortScience [Internet]. 1994 Feb 1 [cited 2023 May 17];29(2):102–3. Available from: l

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