It’s generally not recommended to use vegetable oil that has been expired for 2 years or longer. The safety and quality of the oil deteriorates over time past the expiration date. However, it also depends on how the oil was stored – cooler, darker storage extends shelf life. Smell and taste the old oil to determine if it seems rancid or off before using it.
How Long Does Vegetable Oil Last After Expiring?
The shelf life of vegetable oil depends on several factors:
- Type of oil – Some oils, like canola, soybean and vegetable oil may last 6-12 months past expiration. Olive oil and nut oils may last only a few months.
- Storage conditions – Cool, dark places like the pantry extend shelf life. Warm, sunny places decrease it.
- Package – Oils in metal tins last longer than those in plastic bottles.
- Preservatives – Some manufacturers add preservatives to prolong shelf life.
In general, an unopened bottle of vegetable oil may start to slowly degrade in quality for 6-12 months past the printed expiration date. However, once opened, vegetable oils typically only last 4-6 months before turning rancid.
If your oil is 2 years past the printed date and was opened, it is likely well beyond its prime and unsafe to consume.
Why Vegetable Oil Expires
There are two main reasons why vegetable oils degrade over time:
This is the exposure to oxygen, light and heat that causes the oil molecules to break down. It results in “free radicals” that create unpleasant odors and tastes. Antioxidants help slow oxidation, but become depleted over time. The more unsaturated fat an oil contains, the more quickly it oxidizes.
Moisture & Food Particles
Any droplets of water or particles from food that get into the oil start mini-infestations of mold and bacteria. This causes sour, rancid smells and tastes.
Risks of Using Rancid Vegetable Oil
Consuming rancid oils poses some potential health risks:
- Food poisoning – Bacteria like salmonella or E. coli can grow in old oils and cause nausea, vomiting, and diarrhea if ingested.
- Free radicals – The oxidized fats in rancid oil are pro-inflammatory and increase free radicals in your body, which are tied to cancer, aging, and other chronic diseases.
- Vitamin depletion – Vitamin E and K levels drop in oxidized oil, meaning you get fewer of their antioxidant and anti-inflammatory benefits.
- Gastrointestinal issues – The irritating compounds in rancid oil can cause stomach pain, cramping, and discomfort when consumed.
Some people are more sensitive than others, but rancid oil should always be avoided for food safety.
How to Tell if Vegetable Oil Has Gone Bad
Here are some common signs that your vegetable oil is too old to use:
Rancid oils give off a distinctive, unpleasant aroma – you’ll notice a stale, dusty, paint-like scent that was not present in the fresh oil.
The color changes from clear golden to a murky yellow or even orange shade.
The texture feels thicker and greasier than a fresh oil. It may even be clumpy with food particles.
An easy test is to simply taste a tiny bit of the oil. Rancid oil will have a bitter, unpleasant, metallic flavor.
Check how long it has been open and the expiration date – if it’s over 6 months old, it’s likely rancid.
Oils that have been exposed to heat, humidity, and light will deteriorate faster.
You may notice more foaming and bubbling when using old vegetable oil for cooking.
Bad oils often have a much lower smoke point and will start to smoke at lower heats.
|Signs of Fresh Oil
|Signs of Rancid Oil
|Clear, light gold color
|Murky, yellow or orange color
|Neutral, mild odor
|Stale, unpleasant smell
|Smooth, liquid texture
|Thick, greasy texture
|Neutral, bland taste
|Bitter, unpleasant taste
How to Store Vegetable Oil Properly
To help vegetable oils last as long as possible:
- Buy oils in opaque, airtight containers or metal cans – light exposure speeds rancidity.
- Store oils in a cool, dark pantry or cupboard – heat and humidity break oils down faster.
- Make sure bottles are capped tightly after each use.
- Never pour old oil back into the bottle – always discard it.
- Transfer oil to a smaller bottle if you don’t use it fast enough.
- Don’t repeatedly re-heat and cool the same oil – this increases oxidation.
- Consider refrigerating after opening – the cool environment doubles shelf life but can cause cloudiness.
- Buy oils in smaller quantities if you don’t use them often.
- Consider freezing for long-term storage of over 1 year.
Proper storage extends the shelf life of unopened oils to 1-2 years or beyond the expiration date. Opened oils keep 4-6 months.
What To Do With Rancid Vegetable Oil
If your oil has expired or gone rancid, it’s important to dispose and replace it properly:
- Never use rancid oil for cooking or consumption.
- Discard by placing the oil in an airtight container and throwing away – rancid oil can attract pests.
- Do not pour down the drain where it can clog pipes – instead take to a hazardous waste facility if possible.
- Do not attempt to re-filter or purify rancid oils at home – the decomposition is irreversible.
- Replace your vegetable oil supply with a freshly purchased, unopened bottle.
- Clean any surfaces, pans or utensils the rancid oil touched with hot soapy water before re-use.
- Use open bottles within 2-3 months then replace. Discard if smell, taste or appearance changes.
- Consider switching to more stable oils like avocado, olive or high-oleic oils.
With proper storage and handling, vegetable oil can easily last 8-12 months after purchase. But rancid oils should not be consumed. When in doubt, rely on your senses – if it smells or tastes off, throw it out.
Frequently Asked Questions
Can old vegetable oil make you sick?
Yes, consuming rancid vegetable oil that contains mold, bacteria or free radicals can cause food-borne illness leading to nausea, stomach cramps, vomiting or diarrhea in some cases. The unpleasant compounds can also cause headaches, heartburn and digestive upset in sensitive individuals.
What are the signs of spoiled vegetable oil?
Warning signs of spoiled vegetable oil include foul odors, increased foaming/bubbling when cooking, oil smoking at a lower temperature, thick or clumpy texture, murky appearance, orange color, and a bitter or metallic taste.
How do you restore spoiled cooking oil?
Unfortunately, there is no good way to restore or purify vegetable oil once it has already started to go rancid. The chemical decomposition during oxidation and moisture contamination cannot be reversed at home. Disposal is the only safe option.
Can you use cooking oil past the expiration date if unopened?
Unopened oils may still be useable for a period after the printed expiration date, depending on storage conditions. Tightly sealed, unopened oils stored in cool, dark places could potentially last up to 1 year past date. But if stored in heat or light, they may spoil quicker.
Do oils last longer in the fridge or pantry?
Refrigeration extends the shelf life of oils since the cool environment slows oxidation. Properly stored in the fridge, oils can last 6-12 months past printed date. The pantry is more prone to temperature fluctuations that hasten spoilage. But fridge storage may cause cloudiness as the oils solidify.
How long does vegetable oil last after opening?
An opened bottle of vegetable oil will typically last about 4-6 months with proper storage before degrading in quality and flavor. Pouring out small amounts at a time, minimizing heat and light exposure, keeping tightly sealed, and refrigeration prolongs open oil shelf life. But always rely on smell and taste as the best indicators of freshness.
Vegetable oils that are more than 2 years past their expiration date and have been opened should generally be discarded. The safety, quality and nutritional value of the oil after this point is uncertain. Rancid oils pose health hazards and an unpleasant taste. With unopened oils, the expiration date is more of a guide – cool, dark storage conditions may prolong shelf life up to a year past this point. But once exposed to air, heat and light, vegetable oils have a shorter usable lifespan of around 6-12 months. Always inspect the smell, taste, appearance and feel of older oils before consuming to determine if they have gone rancid. Proper storage helps oils avoid degradation, while signs like odor, color, foaminess, thickness, smoke point can indicate it is time to replace your bottle with fresh oil.