the foes of olive oil

the foes of olive oil

 At Zimms Organics, we work hard to ensure our extra virgin olive oil (EVOO) is among the highest quality on the market. Unfortunately, given its fragile nature, even premium EVOO's quality can quickly decline if not preserved and stored properly.

There are four culprits to the deterioration of EVOO: light, time, temperature, and oxygen. As EVOO is a fruit juice, it is both seasonal and perishable. Unlike wine, its quality and taste naturally diminish over time, but the inclusion of these four elements can rapidly speed up that process.

In 2012, the Australian Oils Research Laboratory began a three-year study that scientifically proved why these specific elements are so damaging to EVOO—specifically its flavor, quality, and chemical structure.

The study notes: “Incorrect storage, even for a short period of time, can reduce the quality of olive oil, sometimes to a level where the oil can no longer be classified as extra virgin.”


When designing the Zimms Organics bottle, we intentionally chose matte paint for two reasons: (1) to protect the EVOO against oxidation and (2) it looks beautiful on any countertop and duals as a piece of art.

With prolonged exposure to light, EVOO can lose many of its valuable nutritional benefits. The Australian research team found that exposure to light significantly decreased the antioxidants in EVOO (especially α-tocopherols) and increased K268, indicating the growth of compounds that produce unpleasant flavors.

Exposure to light significantly affected the organoleptic properties naturally found in EVOO as well (how a given substance affects the senses), so much so that they became nonexistent or even foul.

While the Zimms bottles are not transparent, we still recommend storing your bottle out of direct sunlight to preserve the oil’s potent health benefits and golden goodness for as long as possible!


Interestingly enough, while the aforementioned study found that exposure to light decreased certain antioxidants in the oil, it had very little effect on the polyphenols. However, while light did not affect the polyphenol content, they discovered there was a natural decrease in polyphenols over time, as one variant of EVOO’s polyphenols decreased from 202 mg/kg to 164 mg/kg over several months, despite being stored in the dark. 

We intentionally include the harvest date on all Zimms’ bottles for one reason: olive oil is best young and fresh. Traditionally, in Northern California, our groves harvest their olives in early November when they are on the edge of ripening.

While proper storage practices will extend the oil’s shelf life, its overall quality inherently begins declining a few months after milling and to an even greater extent after it is opened. This is why we recommend purchasing only as much olive oil as you can consume within six months of opening. Most people go through one large bottle (400ml) every 2-4 weeks, so plan accordingly.


To limit oxidation and preserve EVOO for as long as possible, it should ideally be stored between 59°F and 68°F. Although it is convenient to store your EVOO next to the stove or oven for quick access, this will ultimately cause the oil to break down faster, so make sure you tuck your EVOO away safely in a pantry or cabinet!


It is crucial to seal your oil tightly when not in use, as prolonged exposure to air will cause the EVOO to quickly deteriorate and become rancid.

To maintain quality for our precious consumers, Zimms packages all our bottles tightly with a wood and cork top. If you routinely use your oil, we recommend investing in a stainless-steel pour spout. Being airtight as well, this pour spout allows effortless access to your oil while minimizing oxygen exposure.

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