Know how long herb-infused oil lasts, along with the factors that affect its shelf life and other aspects of storage.
Herb-infused oils may smell amazing and taste even better, but the bad news is that they don’t last forever. Here is our detailed article to help you understand their shelf life, which will help you enjoy their benefits without risking spoilage.
What is Herb-Infused Oil?
Herb-infused oil is a flavorful blend that is created by steeping fresh or dried herbs in a carrier oil, such as olive or sunflower oil. This process allows the aromatic and medicinal compounds in herbs like rosemary, basil, oregano, thyme, garlic, and chili to be slowly released into the oil.
 You can do the infusion through cold infusion, where you let herbs steep at room temperature for several days or weeks. It is also done by warm infusion in which oil is infused by heating the herbs and oil together.
How Long Does Herb-Infused Oil Last?
The shelf life of herb-infused oil ranges from 1 to 3 months if you make it with fresh herbs and up to 6 to 12 months when made with dried herbs. It will also depend on how you prepare and store it.
The reason for spoilage is that fresh herbs introduce moisture into the oil, which increases the risk of botulism, a potentially deadly foodborne illness caused by Clostridium botulinum bacteria. That is why oils made with fresh garlic or basil are perishable and should be used within 7–10 days and kept in the refrigerator.
However, oils made with dried herbs like oregano are less likely to cause spoilage because they contain little to no moisture. These versions can remain stable for up to a year if you store them properly in a dark, cool space.
Shelf Life Examples of Popular Herb-Infused Oils
The longevity of herb-infused oils largely depends on the type of herb you use and whether it is fresh or dried. Your fresh basil-infused olive oil can last 1 to 2 weeks when kept in the refrigerator due to the moisture content in the leaves.
Dried rosemary-infused oil can be safely stored in a cool, dark cupboard for 6 to 12 months. This is because dried herbs lack moisture and reduce the risk of spoilage.
What Affects the Freshness of Herb-Infused Oil?
1. Type of Herbs Used
This one plays a vital role! For example, fresh herbs are more prone to introducing moisture and microbes that can spoil oil quickly. If the herbs are dry and have had their water content removed, they will be long-lasting.
2. Oil Base
Carrier oil is also one of the factors that affect the shelf life. Olive oil is rich in antioxidants and resists oxidation, which increases its shelf life. Oils like grapeseed or sunflower can go bad faster.
Pro Tip: You should use cold-pressed extra virgin olive oil for a stable and flavorful base.
3. Infusion Method
When it comes to the infusion method, warm infusion can kill bacteria and extend shelf life slightly, though it may degrade delicate compounds. For culinary use, you should use heat-infused oils that are safer and have fewer contamination risks.
4. Light and Air Exposure
Exposure to light and air speeds up oxidation and rancidity. In this case, oil loses flavor and nutritional value, and may even become unsafe to use.
Pro Tip: Always use amber glass bottles with airtight lids for storing the oil.
Storage Tips to Maximize the Herb-Infused Oil
- Refrigerate: If your infusion includes fresh ingredients (like garlic, basil, or parsley), refrigeration is non-negotiable. Cold storage slows bacterial growth, which increases the shelf life of oil.
- Use Sterile And Dry Containers: Always sterilize jars and bottles before storing oil. Make sure there is no residual water inside the container.
- Use Dark or Opaque Bottles: Light can degrade the oil over time. Amber, cobalt blue, or ceramic bottles help preserve the oil’s quality by blocking UV rays.
- Strain Out Herbs After Infusion: Leaving herbs in the oil may look pretty, but it increases the risk of spoilage. Once the oil has taken on enough flavor, strain it through a cheesecloth or fine sieve.
- Avoid Cross-Contamination: Never dip dirty spoons or fingers into your oil bottle. Bacteria from hands or cooking surfaces can spoil the oil quickly.
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