What happens if you eat expired oyster sauce? (+5 Tips)

In this article, we will answer the questions “What happens if you eat expired oyster sauce?”. Moreover, we will discuss how to tell If the oyster sauce is bad and how to handle your  oyster sauce to prevent its spoilage. 

What happens if you eat expired oyster sauce?

Oyster sauce does not become unsafe for consumption past its expiry if it’s stored correctly. It loses its flavor and intensity past the expiration date and may or may not cause food poisoning 1).

The symptoms of food poisoning may vary from person to person and with the virulence of the mold or bacteria ingested (2). Common symptoms include headache, nausea, weakness, mild fever, loss of appetite, vomiting, diarrhea, and stomach cramps (3-4). 

These symptoms should go away in 1-2 days. If they don’t go away or become intense, consult a doctor. Severe symptoms might include bloody urine, extreme dehydration due to diarrhea, fever above 101.5℉, and diarrhea that persists for more than 3 days (3).

Does oyster sauce go bad? 

Eventually yes. Oyster sauce that is left unopened and properly refrigerated will retain best quality for 2 years. After this time period the taste can get compromised (1). 

How to tell If the oyster sauce is bad?

To check if the oyster sauce has gone bad, look for visual signs of spoilage for example:

  • Mold: Mold growth on the surface of the sauce or around the cap is an obvious indication of spoilage. Do not try to use the rest of the oyster sauce by removing the moldy part. It does not work like that. 

Remember that molds produce dangerous mycotoxins that can make you very sick (5). Discard it immediately because safety first! 

  • Color and flavor: As time passes, the oyster sauce develops a deeper color and a more intense flavor due to the oxidation.
  • Taste: Oyster sauce should have a balanced sweet and sour flavor with hints of caramel flavor to it. If it tastes too sour or has a bitter aftertaste, it has gone bad.
  • Smell: If the oyster sauce gives off a rotten or moldy smell instead of its fresh smell, discard it immediately.
  • Consistency: Ideally, the oyster sauce should have a thick consistency much like a thick broth. If it feels too watery when poured out, It has gone bad.

How long does the oyster sauce last?

The shelf-life of the oyster sauce depends upon its initial quality and its storage. Thus it varies from brand to brand. 

An unopened bottle of oyster sauce will last about 18-24 months depending upon the production quality and storage practices. 

The printed date on the bottle of the sauce will give you a rough estimation of how long the sauce will retain its prime quality. 

A high-quality oyster sauce will retain its freshness for up to a year after its opening. On average, the shelf-life of opened oyster sauce is anywhere between 3-6 months as summarized in the next table: 

In the pantry In the fridge 
Oyster sauce (unopened)Best-by + 3-6 months for best quality 
Oyster sauce (opened)3-6 months for best quality

How to store oyster sauce to prevent its spoilage?

To maximize the shelf life and maintain the quality of your oyster sauce, you should store it properly. Here are some guidelines for properly storing your oyster sauce:

  • Check the packaging: Ensure the oyster sauce is tightly sealed before purchasing it. Avoid containers with broken or damaged seals, as they may compromise the sauce’s freshness.
  • Store in a cool place: Oyster sauce should be stored in a cool and dry location away from direct sunlight. The ideal temperature range is typically between 50°F (10°C) and 70°F (21°C). Avoid storing it near heat sources like stovetops, ovens, or other appliances.
  • Refrigerate after opening: Once you open the bottle of oyster sauce, it is best to store it in the refrigerator. Oyster sauce can be sensitive to heat and humidity, and refrigeration helps slow down the degradation process. 

Make sure to tightly seal the bottle or transfer the sauce to an airtight container before refrigerating.

  • Avoid contamination: Prevent cross-contamination by using clean utensils when scooping out oyster sauce. Avoid dipping dirty or used spoons or utensils directly into the bottle, as this can introduce bacteria.
  • Check expiration dates: Oyster sauce typically has a long shelf life, but it’s still important to check the expiration date before purchasing and using it. Discard any sauce that has expired.

By following these storage recommendations, you can extend the shelf life of your oyster sauce and maintain its quality for a longer period. 

We recommend you to always refer to the specific instructions or recommendations provided by the manufacturer on the packaging for the best storage practices.


In this article, we answered the question “What happens if you eat expired oyster sauce?”. Moreover, we also discussed how to tell If the oyster sauce is bad and how to handle your  oyster sauce to prevent its spoilage.


1. Nguyen THD, Wang XC. Volatile, Taste Components, and Sensory Characteristics of Commercial Brand Oyster Sauces: Comparisons and Relationships. http://dx.doi.org/101080/109429122010492542 [Internet]. 2012 May 1 [cited 2023 Jul 3];15(3):518–35. Available from: https://www.tandfonline.com/doi/full/10.1080/10942912.2010.492542 

2. Bintsis T. Foodborne pathogens. AIMS Microbiol [Internet]. 2017 [cited 2023 May 16];3(3):529. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6604998/ 

3. Milaciu M V, Ciumărnean L, Orășan OH, Para I, Alexescu T, Negrean V. Semiology of food poisoning. Int J Bioflux Soc [Internet]. 2015 [cited 2023 May 10];8(2):108–13. Available from: http://hvm.bioflux.com.ro/docs/2015.108-113.pdf 

4. Lennard LB. Food microbiology and food poisoning. In: Food & Nutrition [Internet]. Taylor & francis Gr…. Routledge; 2020 [cited 2023 May 30]. p. 132–54. Available from: https://www.taylorfrancis.com/chapters/edit/10.4324/9781003115663-11/food-microbiology-food-poisoning-louise-lennard 

5. Tola M, Kebede B. Occurrence, importance and control of mycotoxins: A review. http://www.editorialmanager.com/cogentagri [Internet]. 2016 [cited 2023 Jun 12];2(1). Available from: https://www.tandfonline.com/doi/full/10.1080/23311932.2016.1191103 

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