Hoe bewaar je extra vierge olijfolie het beste? - TheOliveLabel.shop

What is the best way to store extra virgin olive oil?

Introduction

Not all oils are created equal, and extra virgin olive oil (EVOO) is no ordinary oil. EVOO is a very special, pure natural product packed with organic compounds such as healthy fatty acids, vitamin E, and polyphenols (a unique form of over 30 different types of antioxidants), all of which are important for your health. These valuable fatty acids, vitamins, and antioxidants make your EVOO healthy, but also susceptible to spoilage.

Fortunately, there are several things you can do yourself to prevent your EVOO from spoiling unnecessarily quickly. In this article, based on scientific research and practical experience, you will learn how best to store your EVOO to prevent spoilage for as long as possible and keep your valuable EVOO fresh for longer.

If you don't feel like reading everything, extra virgin olive oil stays healthy and flavorful longest when stored in a cool, dark, and well-sealed place, possibly even in the refrigerator or freezer for extended shelf life.

1. What can olive oil not tolerate?

As mentioned, EVOO is a natural product, and as everyone knows, natural products, such as fresh vegetables, milk, cold cuts, etc., spoil quite quickly in (UV) light, air (oxygen), and heat. For example, leave cold cuts and a glass of milk in the warm sun, and within a few hours, you won't want to eat them anymore. Pack the product vacuum-sealed and store it cool, and it will remain good for days or weeks. It is no different with EVOO. You should protect EVOO as well as possible against:

  • Light activates chlorophyll (green pigment) → this accelerates oxidation (the biological compounds break down), causing polyphenols and antioxidants to disappear. EVOO in a transparent bottle on a sunny windowsill can turn rancid and orange within a few days.
  • Air (oxygen). As soon as the bottle is opened, the oil reacts with oxygen. This process (oxidation) causes chemical reactions that affect fatty acids → the oil eventually turns rancid, and the quality deteriorates.
  • Heat accelerates all these processes → the warmer it is, the faster the healthy substances break down.

All three accelerate the spoilage process, whereby healthy antioxidants break down and turn into oxidants. The health value, taste, and smell deteriorate.

Therefore, it is important to always store your olive oil in a dark, well-sealed, and cool place: this way, its taste and health benefits will remain intact for the longest time.

2. How long can you store olive oil?

Time is the fourth enemy of EVOO. As with all other fresh, natural products, quality will inevitably deteriorate over time. However, how you store your EVOO greatly influences the effect of time on quality and how long your EVOO remains fresh and healthy.

Our guideline is, provided it is stored cool (12 – 21 degrees) and in a dark place:

  • Unopened bottle (little oxygen): preferably use before the best before date. In the EU, premium EVOO has a best before date of 18 months after bottling.
  • After opening (more contact with oxygen): preferably use the oil within 3 – 4 months. The fresher, the better. The closer you get to the best before date, the faster your oil will deteriorate.

If you store the bottle cool, dark, and sealed, your fine olive oil will remain good for a long time.

3. Storing extra virgin olive oil cool

Cool storage means temperatures between 12 and 21 degrees. A little higher, if it's summer, your EVOO won't spoil immediately, but it won't benefit its shelf life. Therefore, avoid storing your EVOO near a heater, next to the stove, on the extractor hood above the stove, or on the windowsill near the kitchen window, for example.

Can you store extra virgin olive oil in the refrigerator?

Is it a good idea to store your premium EVOO in the refrigerator? The answer is: yes, there are advantages, but also a few, relatively minor, disadvantages.

Advantages of storing in the refrigerator

  • Longer shelf life: at lower temperatures, oxidation proceeds noticeably slower. Polyphenols – the healthy compounds in olive oil – are preserved longer due to the lower temperature (supported by this study published in the Journal of Agricultural and Food Chemistry investigating the stability of phenols at different temperatures).
  • Extra protection: the oil is better protected against heat and light, two important factors that affect quality.

Disadvantages of storing in the refrigerator

  • Cloudiness & solidification: At a refrigerator temperature between 4 and 7 degrees Celsius, premium EVOO will become somewhat cloudy over time. It will look like flakes are floating in it. If you wait a little longer, your EVOO will become somewhat more viscous. This makes pouring a bit more difficult but is perfectly normal for good quality EVOO and does not affect the quality. The cold is actually beneficial for the quality. The flakes and viscosity disappear as soon as the EVOO returns to room temperature.
  • Taste: prolonged cooling can slightly adversely affect the smell and taste. However, most people will barely notice the difference.

Why does olive oil solidify in the refrigerator?

EVOO largely consists of oleic acid, a fatty acid that solidifies around 6–10 °C. That's why you see clumps or flakes when the bottle is in the refrigerator, or when you receive your order when it's cold outside. If you bring the bottle back to room temperature, the oil will become clear and liquid again within a few hours.

Can you freeze olive oil?

Yes! Very well, in fact. We have found at least two studies (one here on the ScienceDirect website and one here on Springer Nature Link), which show that you can indeed freeze EVOO for an extended period. Even after 12-18 months, there is almost no difference in quality after thawing.

The conclusions of these studies are:

  • ScienceDirect: Even after 18 months, frozen EVOOs showed a superior quality profile compared to those stored at room temperature. The aroma profile also remained stable after 12 months of storage in the freezer. The differences in scent and taste profile were negligible.
  • The second study also concludes that freezing at -20 °C helps preserve the taste, smell, and healthy compounds of premium extra virgin olive oil much longer than at room temperature. After thawing, there is hardly any difference from fresh oil: the taste and nutritional value largely remain intact.

If you want to store olive oil for a longer period without loss of quality, you can freeze EVOO.

Practical advice

  • Daily use: store your sealed bottle in the dark and away from a heat source. Use within 3 to 4 months.
  • Stock bottle or bulk packaging: store dark and especially cool, for example in the cellar or refrigerator. Fill a smaller bottle for the kitchen and table.
  • Storing for longer than six months: then you can consider freezing your EVOO.

4. Why EVOO is often packaged in a dark bottle

Light is the number 1 enemy of EVOO. Because the valuable natural polyphenols, chlorophyll, and vitamins are sensitive to (UV) light, premium EVOO is almost always packaged in a dark bottle that keeps light out. This keeps your EVOO fresh for longer.

It is not wise to buy a bottle of olive oil packaged in a transparent bottle. EVOO really cannot tolerate (UV) light, and you never know how long that bottle has been exposed to daylight. There is a chance that this oil, although new, may have already turned rancid in the bottle.

Some producers still choose to package their premium EVOO in a beautiful but transparent glass bottle. That looks very nice! As long as it has not been exposed to daylight, this olive oil can, of course, still be good. Tip: store it in a kitchen cabinet and only bring it out when guests arrive and you want to show off the bottle.

During a vacation in Greece, I saw various types of olive oil in glass bottles and flasks in the full Greek sun in the many souvenir shops everywhere. This oil, regardless of the brand, whether with herbs or not, etc., becomes completely rancid and inedible after a day or two in the sun.

Always choose a dark bottle. But even a dark bottle is preferably not stored in direct daylight: UV light can still cause damage (See an article in Olive Oil Times here). Research from Italy shows that even dark green glass bottles do not fully protect olive oil from light. With prolonged exposure, oxidation increases, and the content of phenols and polyphenols—precisely the substances that make extra virgin olive oil so valuable—decreases. Storing your bottle of olive oil by the kitchen window is really not an optimal place.

Packaging that better blocks light and oxygen, such as multi-layer bag-in-box systems with an aluminum barrier, demonstrably preserves quality better during storage and transport.

5. The advantages of Bag-in-Box (BIB) packaging

Premium EVOO is increasingly being packaged in a bag-in-box. This is a bag with a tap inside a cardboard box. Many are familiar with this from often cheaper wines. However, bag-in-box packaging extends shelf life better than glass or tin, because air and light are completely kept out. This packaging therefore has a number of important advantages:

  1. Protection against light. The cardboard box keeps 100% of the light out.
  2. Protection against oxygen. The inner bag shrinks as you draw oil → no air gets in. This keeps the oil fresh much longer than in a bottle that is constantly opened.
  3. Longer shelf life. Scientific tests show that oil in a bag-in-box retains its polyphenols and taste up to 4 times longer compared to glass.
  4. Convenient to use. With a tap, you can easily dispense small amounts without spilling.
  5. More sustainable. Cardboard and the bag are often more recyclable and lighter in transport than glass. As a result, the CO2 footprint is 60% lower than with glass.

What about a nice traditional tin can?

A tin can may look good but does not benefit shelf life.

EVOO in a tin can had deteriorated in quality so much after 80 days at 21.5 degrees that it no longer met the requirements for EVOO. In other words, the olive oil had turned acidic. According to European legislation, EVOO may contain a maximum of 0.8% free fatty acids, expressed as oleic acid. The lower this percentage, the better the quality. As soon as that percentage rises, the oil will smell increasingly musty and become somewhat rancid.

At a temperature of 36.5 degrees, after 60 days, the oil in the tin was no longer EVOO. See an article in the Olive Oil Times here on this topic, with a reference to the study.

A dark bottle is better, and a bag-in-box is even better. The same study showed that EVOO in a bag-in-box still qualified as extra virgin olive oil after 120 days of storage at 21.6 degrees (room temperature). Even after 80 days at a temperature of 36.5 degrees, the oil maintained EVOO quality.

EVOO in a bag-in-box can be kept fresh much longer.

6. Summary: the 5 golden rules

Tip Advice
1. Dark Buy EVOO in a dark bottle or bag-in-box and store it in a dark place
2. Cool storage Ideally 12–21 °C. Refrigerator (4-7 °C) is acceptable. For long-term storage, you can freeze EVOO
3. Avoid oxygen Always seal bottles tightly
4. Shelf life at room temperature Unopened, use before the best-before date; opened, use within 3–4 months, but no later than the best-before date.
5. Smell & taste Fresh & fruity = good; flat & rancid = do not use

Conclusion

Extra virgin olive oil remains healthy and flavorful longest if you store it cool, dark, and airtight. After opening, use within a few months but in any case before the best-before date, and always trust your senses. This way, you can optimally enjoy the unique taste and health benefits of this liquid gold.

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