What should you be looking for on the label?
Here we will explain why olive oils marketed with an "early harvest" date on the label are very often undesirable compared to olive oils with a "best before" date on their label.
Some of the more aggressive marketers out there will tell you to only look for an early harvest calendar date on the label to determine you have the "best" in your hands. This is deeply flawed and done solely to pull your attention away from other important factors. The same aggressive marketers will tell you not to "trust" best before dates.
"Early harvest" however does not represent a calendar date (it's not a question of whether a November 1rst harvest is "earlier" than a November 30th one). Early harvest is only relative to a specific individual olive grove and whether the olives were harvested in the early days of the harvest of that specific grove or later. Different olive groves get harvested at different times due to a variety of factors. Those are predominantly:
Using the example of Greece as a growing region (where we grow the olives for OPUS):
* olives ripen earlier (by about 2+ months) in the south of Greece in Crete, (which is the 2nd largest olive producing region in Greece) than in the north. This means that an early November oil in Crete is more ripe than a December oil in the north of the country. You may well be buying that ripe Crete oil at the expense of the more underripe, much higher quality northern Greece oil, that has a later harvest date. You can observe similar agricultural patterns in the UK. Apples ripen earlier in Kent than they do in Scotland. In our Northern Hemisphere, fruit simply ripens faster in the south of the country than in the north of it.
* olives ripen earlier at sea level than they do at altitudes of say 500 meters. Opus has a field at near sea level and one at much higher altitude on the mountain. Harvest on the 2 fields is up to 2 months apart. So how can the customer distinguish which one was harvested riper without extremely close knowledge of the product's provenance? Answer: they can't from just reading a label.
* different olive varieties ripen at different times, which has to do with the size of the olive variety fruit, the amount of water it needs to absorb to ripen and other factors specific to the olive variety itself and the soil composition of where it grows. The differences between olive varieties are also up to 2 months apart. A customer would need very specialised, agronomist and/or botanist knowledge to know the differences.
* this is an important one: olive oil that has been left unfiltered, will oxidise (go rancid) within 2-3 months of its production, even if it was made from early harvested olives, losing a great deal of its nutritional and culinary value. They will say to you "but look! It is "clear", it has "naturally" been filtered by the solids slowly accumulating at the bottom" - beware! Because this is olive oil that has already turned bad, giving a bad name to good olive oil. All because the seller pockets the money that filtering costs, all the while continuing to flog it off to the hapless "early harvest"-chaser for months to come, at excessively high prices, by marketers without integrity.
There are also other points to consider:
* olive oil that is higher than average in its content of antioxidants (and is properly filtered) will stay "fresh" for up to 12+ months longer, as the antioxidants preserve the oil. The producer alone will be able to give correct guidance on how long their specific oil, produced with their methods, will reliably last.
* harvest dates are not regulated by law and are difficult to truly ascertain to begin with. Anyone can, in theory, declare whatever date they like on a label. How can you trust that an oil that hits UK shelves with great fanfare in March or April (the "new" oil has arrived ... as if it's some cheap Beaujolais nouveau ...), has actually been harvested 4 or 5 months earlier, in early November, as its label declares? What on earth took it so long to get here to the UK?? Don't be easy prey to the marketers.
* it is most often olive oil brands run by middlemen/-women and not by producers themselves, that hark on about, often spurious, harvest dates. This because it's a gimmick, there to divert the consumer's attention. You see, a producer must be able to stand behind their product no matter what, they are tied to it for the long term and must be able to vouch for it. Middlemen don't care - they are by nature short-termist. They just want to "flip" and "push out" the batch they acquired whichever way they can without really caring about the end consumer. They themselves have no idea or control over when the batch they were sold to themselves, to sell on, was actually harvested in reality ... They will happily sell you that unfiltered "early harvest" oil that has been sitting in their warehouse for a year and been rancid for 10 months already. Tomorrow they will just "flip" someone else's batch ... They don't know and often cannot truly assess what was sold to them. They rely on most British consumers not having much knowledge of olive oil and take no pride in presenting a decent product that is fairly priced. The UK customer finds themselves with an overpriced product and with misleading advertising. Bad operators like this are a headache for the olive oil world and muddle the waters for those with integrity.
* Of course there's also potential fraud. Batches brought to the UK in bulk and bottled here, can also easily just be rebottled here when oil is left-over oil at the end of the season. They may also be mixed it with something else, sold as a "blend" and stamped with a brand new harvest date ... It's actually the main reason some operators bottle batches brought from afar in the UK instead of the oil's own country of origin. Glass bottles full of oil that have traveled to the UK are uneconomic to be returned back for rebottling - it's simply not cost effective. Bottling in country of origin is a sign that the producer is doing the right thing. Not so for a UK-bottled olive oil. No one is the wiser as to what its real path was, irrespective of date stamps. At OPUS when there is any left over oil at the end of the season (which is rare), it is all donated to local UK food charities.
In the olive oil world "early harvest" is best. Olives that are removed from the tree early in the season and are still under-ripe, green with tinges of purple here and there, are at the height of their polyphenol antioxidants level. They give the most fresh herbal aroma to olive oil and have the highest nutritional value. You won't know from a date alone whether what you're being sold to is an actual early harvest or not.
The actual truth is that the "Best Before" date gives you a reliable guideline by the producer as to what the minimum time is by when the product is in its best condition.
Harvest date must be evaluated in the context of the totality of the environment and is otherwise meaningless. Pay attention to where a seller stands in the value chain and what their natural motives are. Don't be fooled by loud, pushy, nonsense marketing.