Fresh extra virgin olive oil basically is fruit juice. (Yes, olives are a fruit, the fruit of olive trees!) So, just like other fruit juices, the oil from an olive is perishable. And, unlike wine, extra virgin olive oil doesn’t improve with age; it's actually just the opposite. How you go about storing olive oil will make a huge difference!
We at California Olive Ranch go to great lengths to ensure our oil stays as fresh as possible. We have robust storage programs for all of our extra virgin olive oil – both the oil we harvest and mill in California, and the extra virgin olive oil grown by our partners in other regions across the globe. At our facility, we store all the extra virgin olive oil in stainless steel tanks that are nitrogen flushed and temperature controlled, and we do an evaluation of all our partner growers’ facilities to make sure they have proper storage capabilities as part of our supplier audits. The stainless steel tanks to protect the oil from three of the four enemies of olive oil: light, heat and oxygen. This storage system helps preserve the freshness of the extra virgin olive oil until it’s ready for bottling.
While it is unreasonable (and unnecessary) to expect the average home cook to have a storage system like ours, there are some tips we offer to combat against the same four enemies of olive oil.
LIGHT
Your extra virgin olive oil does not like to be left out in the daylight! Minimize or eliminate light exposure at all times – it causes olive oil to degrade. Avoid storing your oil by a window and avoid storing it in clear glass. We chose our dark green bottle for a reason, the color helps filter out the damaging ultraviolet rays. Dark cupboards or pantries are best for storage, and ideally not the one near the range (see below).
TEMPERATURE
The optimal storage temperature for olive oil is about 65°F. While many people keep their bottle of extra virgin olive oil near the stove for easy access, this is going to cause the oil to rapidly move towards rancidity. Avoid storing your extra virgin olive oil near the range, or in direct sunlight, opting for a cool, dark, cupboard instead.
OXYGEN
We pick our olives and rush them to the mill for crushing ASAP to limit their exposure to air after harvesting and the same goes for while the oil is milled. At our mill, we store our oil in airtight tanks that are sparged with nitrogen to keep oxygen out and cap our bottles with nitrogen to minimize oxygen in each bottle. Protect your oil from being exposed to air! Air can degrade oil quality and the process starts once the oil is exposed to air. While of course there will be some exposure to air once you open the bottle, be sure to keep the lid closed tight when you aren't using it. We definitely don't recommend you transfer the oil to a new container on your counter nor using special open pourers as all of this introduces oxygen.
TIME
The time from when we pick the olives to when we crush them must be as brief as possible. Once bottled, the oil has a two-year shelf-life. And once you open your oil, you’ll want to use it relatively quickly; our recommendation is within 30 to 60 days. This helps the oil retain its peak flavor and avoid oxidation that can lead to rancidity. While we do understand wanting to save the 'good stuff' for special occasions, you are not doing any favors to the integrity of the oil by letting it sit on the shelf.
A NOTE ON HARVEST DATES
We list harvest date on every bottle as an indicator of quality and freshness. Our general recommendation is to look for the most recent years’ harvest date, as many of you know.
When addressing an extra virgin olive oil featuring the oil of both California and growing regions in the Southern Hemisphere, determining the most recent year can be a bit confusing.
Olives are harvested once a year, in autumn. This lands between October and December in the Northern Hemisphere and between April and June in the Southern Hemisphere. The difference in timing is of course due to the difference in seasons between the two hemispheres. Harvest occurs during the autumn, which arrives in opposite times of year in opposite hemispheres.
Olive oil from the most recent California autumn harvest typically arrives on store shelves the following Spring.
Throughout the year the harvest date you see on your bottle will fluctuate, depending on the hemisphere where the olive oil was harvested, the racking process, and the speed to which your local store sells through its olive oil supply.
We are excited that our Global Blend features oil from both hemispheres because this means we can feature the freshest extra virgin olive oil from each harvest season twice a year instead of once! In our spring in United States, the fresher oil is from the Northern Hemisphere, and by the end of summer we are introducing new fresh oil from regions in the Southern Hemisphere. This means fresher oil and that is always a good thing!
While harvest date is one important note of freshness on a label, paying close attention to the best by on the back of the bottle is also an important indicator, so take both into account, and trust that we have taken good care to ensure the freshness of the extra virgin olive oil in your bottle.
We hope this information has been helpful! Please refer to storing olive oil for more information, or write to us at CustServ@cal-olive.com.