All About Cooking oil
Your complete guide to cooking oil - discover how to store it properly, identify when it's gone bad, and find the best substitutes for your recipes.
How Long Does Cooking oil Last?
Storage times and freshness tips for cooking oil in different conditions.
Safety first: This guide provides general information. When in doubt, throw it out! Trust your senses and err on the side of caution. If something smells, looks, or tastes off, don't consume it.
Unopened, Room Temperature (Pantry)12-24 months (refined oils), 6-18 months (unrefined/virgin oils like EVOO), 3-12 months (delicate nut/seed oils like flax, walnut)
Signs of Spoilage
Typically no signs of spoilage if unopened and stored correctly. The primary concern is approaching or exceeding the 'best by' date.
How to Check
Rely on the 'best by' or 'expiration' date provided by the manufacturer. If no date, assume it's good for 1-2 years from purchase if stored optimally. If the packaging is damaged or bulging, do not use.
Storage Tips
Always store cooking oils in their original, tightly sealed containers. Keep them away from stoves, windows, and other heat/light sources which accelerate rancidity. Dark glass bottles or opaque containers offer better protection than clear ones.
Opened, Room Temperature (Pantry)6-12 months (refined oils), 3-6 months (unrefined/virgin oils like EVOO), 1-3 months (delicate nut/seed oils like flax, walnut, grapeseed)
Signs of Spoilage
Rancid smell (like old crayons, metallic, bitter, stale nuts, or 'off'), bitter or stale taste, sometimes a slightly sticky or gummy texture, or a noticeably darker color than when fresh.
How to Check
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Smell Test: Open the bottle and take a deep whiff. Fresh oil should have a neutral, clean, or characteristic aroma (e.g., olive oil's fruity scent). If it smells 'off,' like old crayons, metallic, or simply unpleasant, it's likely rancid. This is the most reliable test.
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Taste Test (small amount): If the smell is ambiguous, put a tiny drop on your tongue. Rancid oil will taste bitter, sharp, metallic, or stale. Fresh oil should taste clean and smooth.
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Visual Inspection: Check for any unusual cloudiness or sediment that wasn't present when first opened (though some unfiltered oils naturally have sediment, and olive oil can get cloudy in cooler temps and clear up). A significant darkening of color can also be a sign.
Storage Tips
Always keep the container tightly sealed to minimize exposure to air, which is a major contributor to rancidity. Store away from heat and light. Do not pour used oil back into the fresh oil container, as this can introduce contaminants and accelerate spoilage.
Opened, Refrigerated (for extended freshness)8-18 months (refined oils), 4-9 months (unrefined/virgin oils like EVOO), 2-5 months (delicate nut/seed oils like flax, walnut, grapeseed)
Signs of Spoilage
Rancid smell (like old crayons, metallic, bitter, stale nuts, or 'off'), bitter or stale taste. Cloudiness and solidification are normal for some oils (e.g., olive oil) in the fridge and are not signs of spoilage.
How to Check
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Allow to warm: If the oil has solidified, let a small amount come to room temperature before performing smell and taste tests.
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Smell Test: As with pantry storage, sniff for rancid odors.
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Taste Test (small amount): Taste a tiny drop for bitterness or staleness.
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Visual Inspection: After warming, check for any unusual particles or persistent cloudiness that doesn't dissipate.
Storage Tips
Refrigeration is particularly beneficial for delicate oils rich in polyunsaturated fats (e.g., flaxseed, walnut, grapeseed, sesame) as it slows down oxidation. Olive oil can be refrigerated, but it will become cloudy and solidify; this is harmless and reversible at room temperature, but can be inconvenient. Ensure the container is tightly sealed to prevent the oil from absorbing odors from other foods in the fridge.