In a few words: Most olive oil labels don’t give you much useful information, so knowing how to buy olive oil comes down to a few clear checks like harvest year/date, origin, grading, packaging, and lab-tested polyphenol figures. Once you focus on those, choosing a good bottle becomes much simpler and less about marketing claims. The rest is mostly about freshness and transparency rather than branding.
Olive oil is not the type of product that consumers should decide to purchase on price alone, as such a decision could probably end up having consumers wonder why the bottle at the back of the cupboard tastes of nothing at all.
At MasWorth, we spend a fair amount of time explaining our own oils - the exact harvest date including the harvest year, the independent lab results and certifications, the polyphenol numbers - but we get asked just as often about how to buy olive oil in general. So here's the honest version, an extra virgin olive oil guide built around what actually matters: from choosing a bottle to spotting one that isn't quite what it claims to be.
How to choose and read the label
Olive oil labels can look impressive on the surface, but a lot of what matters gets left out or hidden in plain sight. If you know what to look for, you can quickly tell whether a bottle is genuinely fresh, traceable, and properly made.
Harvest date, not best-before
A best-before date can legally sit up to two years in the future. Olive oil doesn't improve with time the way wine does; it slowly loses flavour and antioxidant content from the moment it's pressed.
Showing the exact harvest period with the year included tells you the thing that actually matters: when the olives went from tree to press. As a rough rule, look for oil within 12-18 months of harvest. If a bottle only carries a best-before date with no mention of harvest timing, or only the month is mentioned without a reference to the year, that's often a choice rather than an oversight - it's harder to sell an oil as fresh once you can see exactly how old it is.
This is exactly why every MasWorth bottle carries a clear harvest date with the full month and year information rather than just a shelf-life claim - so you can see for yourself.
A named place beats a vague one
A specific estate, valley, or country of production tells you the oil came from somewhere traceable. "Produce of the EU," or a blend of several countries, usually means growers and harvests have been pooled together and blended for a consistent taste rather than a standout one.
PDO (Protected Designation of Origin) and PGI (Protected Geographical Indication) are worth looking out for on the label, but consumers very often misunderstand their function and consider them as a quality badge rather than a simple origin information. Two olive oils with the same PDO or PGI badge can be very different in quality and overall characteristics.
Know your grades
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Extra virgin - mechanically extracted, no heat or chemical processing, acidity under 0.8%, and it has to pass sensory testing for taste and aroma.
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Virgin - a step down. Higher allowed acidity, lower sensory bar.
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"Olive oil" or "light olive oil" - a blend of refined oil and a small amount of virgin oil. Refining uses heat and chemical processing, which strips out both flavour and much of the polyphenol content.
Check the ingredients list, too - it should say "olive oil" and nothing else.
Bottle colour matters more than people think
Light degrades olive oil, full stop. A clear glass bottle might catch the eye on a shelf, but it's working against the oil inside from day one. Dark glass or tin is the safer bet - basically the baseline if you want the oil to stay in good condition for longer.
Look for numbers, not adjectives
Words like premium, superior, or gourmet don’t really mean anything in a regulated sense - anyone can print them on a label. What actually tells you something useful is whether the oil meets the Health Claim category and whether the seller publishes a certificate with the level of lab-tested polyphenols.
Most oils on UK supermarket shelves don’t publish this at all, which usually isn’t an accident. At Masworth, we publish our own polyphenol figures so you can see exactly what you’re getting, rather than relying on marketing language - including our MasWorth Family Groves and November Olive Oil.
If you want to go a bit deeper into what actually counts as high polyphenol oil in practice, we’ve broken it down here: How to Choose the Best High Polyphenol Olive Oil in the UK.
H2: How to tell if olive oil is fake
“Fake” olive oil isn’t always fake in the dramatic sense. It can mean a few different things - from perfectly real oil that’s just old or badly stored, to oil that’s been mixed with cheaper refined oils.
A well-known 2010-2011 study from the UC Davis Olive Centre found that many imported oils labelled as “extra virgin” didn’t meet international standards. But a lot of that came down to oxidation, storage and handling rather than deliberate fraud. Even UC Davis has since been careful about how that study is talked about - especially the idea that “most olive oil is fake”.
The simple truth is this: the most common issue isn’t cheating, it’s freshness. Oil that’s been sitting around too long, exposed to heat or light, loses what makes it good in the first place. And by the time it hits your table, it usually just tastes flat and a bit lifeless.
A few checks that actually work:
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Smell it first. Fresh extra virgin olive oil should smell green and alive - grassy, fruity. If it smells flat, it could be oxidised or rancid.
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Then give it a taste. A slight cough or peppery “catch” at the back of the throat is actually a good sign - that’s oleocanthal, one of the natural compounds linked with olive oil’s anti-inflammatory properties. No bite at all usually points to something refined, tired, or both.
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Skip the fridge test. You might have seen the idea that good olive oil should go cloudy or solid in the fridge. It’s not reliable - some genuine oils don’t behave that way, and some lower-quality ones still do. Testing bodies have been clear it’s not a meaningful way to judge quality.
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And pay attention to how it’s sold. Loose oil, unlabelled bottles, or prices that feel too good for the origin are worth questioning. The easiest oils to trust tend to be the ones that are open about exact harvest dates, origin, and lab-tested quality - no mystery, just transparency.
We've gone deeper into how to actually taste olive oil like you know what you're looking for, if you want to get better at spotting the difference.
A note on the word "November"
Worth flagging directly, since we see it causing confusion: olives picked in October or November, could be used as a promising marketing sign - but simply printing "November" or "November harvest" on a label tells a buyer nothing beyond a month. This oil could be from almost two years back if the exact year is not mentioned with any reference and there is a good chance the sellers using these sign could try to confuse consumers by trying to associate their oil with our NOVEMBER olive oil brand.
Mentioning the month only says nothing about acidity, olive variety, extraction method, whether the oil is organic, or how it actually tastes once pressed.
Two oils picked in the same November can be entirely different in quality.
NOVEMBER is the name we've given our own flagship oil, rooted in four generations of olive growing and built around standards most producers simply don't meet: genuinely early picking, groves in Greece we've worked for generations, and a polyphenol figure measured each harvest year - that is independently certified rather than just claimed.
You'll only find the real thing sold directly through MasWorth. If you ever spot it listed somewhere else, we'd rather you check with us first than assume it was genuine.
Take a look at our November Olive Oil article if you want to see how our oil stacks up against what else is available.
Choosing extra virgin olive oil for health versus choosing for cooking
If you’re looking for the best olive oil for health, the key factor is a measurable polyphenol content. Make sure to check out our guide to high polyphenol olive oil to learn more about these amazing little compounds.
If health is the priority
Polyphenol content is the number to chase - not "extra virgin" on its own, which says nothing about polyphenol levels.
UK law (carried over from EU rules, now enforced by the Food Standards Agency) permits one regulated health claim here: that olive oil polyphenols help protect blood lipids from oxidative stress. To carry it legally, an oil needs at least 5mg of hydroxytyrosol and related compounds per 20g serving - roughly 250mg/kg. Most supermarket olive oils don’t reach that level, which is a big part of why you rarely see the figure on the label.
Higher polyphenol levels tend to come from earlier, under-ripe harvests. After that, heat and time do most of the damage - polyphenols break down at high temperatures, so using the oil raw helps preserve more of them than cooking does. The claim itself is based on around 20g a day, roughly a tablespoon and a half.
If cooking is the priority
When it comes to the best olive oil for cooking, what really matters is how steady it stays under heat and how it fits into everyday cooking.
Heat matters here, but it’s not quite the trade-off people often think it is. Extra virgin olive oil has a smoke point of roughly 190-210°C, which comfortably covers most everyday cooking like sautéing, roasting, and shallow frying. The idea that it can’t handle heat, or should only be used raw, is mostly a myth.
In fact, a good extra virgin oil often holds up better than many refined oils, thanks to its natural antioxidants. Those help protect it from breaking down as quickly under heat, even if the smoke point on paper looks lower.
That said, for very high-heat cooking like deep frying or hard searing, a more neutral, cheaper oil makes sense - you’re not really paying for flavour at that point anyway.
Save your best bottles for the moment heat isn't involved: stirred through a finished dish, drizzled over vegetables, or used as a dip, where its flavour and phenolic content are left untouched.
The short version
Five things do almost all the work: an exact harvest reporting date with the year explicitly specified instead of a best-before, a specific country or place instead of a vague mix of countries, an accurate grade, dark glass, and a polyphenol figure you can actually check through a lab certificate. Everything else on the label, the fonts, the adjectives, the story about the grove, is decoration.
Next time you're standing in front of a shelf of near-identical green bottles, that's what's worth ten seconds of your time: turning it over and seeing how many of those five things are actually there. Once you understand that, how to buy olive oil becomes less about choice and more about knowing what to ignore.
Or, if you’d rather skip the guessing, that’s exactly what we focus on at MasWorth - properly early harvest oils, real lab-tested polyphenol figures, and bottles designed around keeping the oil in good condition from the moment it’s made.
You can read more on the MasWorth blog, including a deep dive into how fresh extra virgin olive oil can help you live longer, or explore our oils if you’d rather just pick something you can trust straight away.
