Unfiltered Olive Oil: Why We Filter Ours, From a Producer Who Owns the Mill

Unfiltered olive oil is extra virgin olive oil bottled straight from the press with the fruit particles and water still suspended in it, which is why it looks cloudy. It is sold as the more natural, more authentic choice. Here is the position of someone who owns the grove and the mill: unfiltered oil is wonderful for about a week or two after pressing, and after that the thing that makes it cloudy is the thing that ruins it. We filter every bottle we sell, and this is why.

What "unfiltered" actually means

When olive paste is spun in the centrifuge, what comes out is oil plus a small amount of fruit pulp and vegetation water. Filtering passes the fresh oil through cellulose or cotton to pull those out. Skipping that step leaves them in the bottle. That is the entire difference. Nothing is added, nothing is heated, and both versions are extra virgin if the chemistry and the taste panel say so.

In the first days after pressing, the unfiltered version is a real pleasure. In Tuscany they call it olio nuovo and drink it on toast in November, and if you have ever stood in a mill in October with warm bread and a cup of the oil coming off the line, you know why. The pulp adds body and a green, almost vegetal roughness. I am not against that experience. I am against selling it in a bottle that will sit on a shelf in Ohio in March.

Why the cloudiness turns on you

Those suspended particles are fruit. Fruit ferments. The water droplets carry enzymes and microorganisms. Sitting in a bottle for weeks and months, the sediment settles to the bottom, ferments, and gives the oil the defect tasters call fusty or muddy, a flat, sour, sweaty note that is the opposite of fresh. The water also speeds up hydrolysis, which raises free acidity, and the particles accelerate oxidation. Studies comparing filtered and unfiltered oils in storage find the same thing every time: they start close together, and the filtered oil holds its quality far longer.

So the honest window for unfiltered oil is short. If you own the mill, as we do, take a jug of unfiltered oil home in harvest week and finish it within one to two weeks. That is what my family does. It is a seasonal treat with a clock on it.

Why we filter the day the oil is made

We are not selling oil to people standing next to the press. We are shipping it across an ocean and then across the United States, to our own warehouse in Brooklyn, to thousands of shops, and to kitchens where a bottle may take three months to finish. A bottle that is only right for two weeks is the wrong product for that job.

So at our mill in Milas, the oil is filtered the same day it is pressed, before the pulp has any time to sit and work on it. Then it goes into stainless steel tanks under food-grade nitrogen, below 16°C, in the dark, until it is bottled to ship. The result is an oil that still tastes like the top of its range a year after harvest, with the polyphenols that make it worth buying still in the bottle. Our Early Harvest tests at around 500 mg/kg total polyphenols by HPLC to IOC Doc 29 at pressing, and the reason that number still means something by the time you open it is that we took the fruit out before the fruit could take the oil down.

Why so many brands advertise unfiltered anyway

Because it sounds like a virtue and it costs nothing. Filtering is a real expense: equipment, filter media, labor, and a small loss of oil that stays in the filter. Skipping it saves money at the exact moment a brand can put "unfiltered" on the label and charge more for it. The word does the marketing and the shelf does the damage, slowly, where nobody sees it.

I do not think most of these brands are lying about their process. I think they have borrowed the romance of the mill floor and attached it to a bottle that will never see a mill floor again. If a brand tells you its unfiltered oil is better for you, ask them one question: how long after pressing does the bottle reach the customer? If the answer is months, the cloudiness is not a feature.

When unfiltered olive oil is worth buying

Three situations, and they all have the same clock. First, you are at or near a mill during harvest and the oil was pressed this week. Second, a producer ships a small olio nuovo release within days of pressing with the pressing date on it, and you plan to finish it fast. Third, you press your own. In every other case, buy filtered oil with a harvest date, keep it cool and dark, and you will drink a better oil for longer.

Cloudy is not a quality signal. The harvest date, the acidity, the polyphenol number with its method, and the pepper at the back of your throat are the quality signals. Here is how to read all of them.

Frequently asked questions

Is unfiltered olive oil better than filtered?

For the first week or two after pressing, it is a richer experience. After that, filtered oil is better, because the suspended fruit and water in unfiltered oil ferment and speed up rancidity. For any bottle that will sit on a shelf or in a pantry, filtered wins.

Does filtering remove polyphenols?

Not in any way that matters. Filtering removes pulp and water, not the phenolic compounds dissolved in the oil. What destroys polyphenols is time, heat, light, and oxygen, and unfiltered oil loses them faster in storage. Our filtered Early Harvest tests at around 500 mg/kg by HPLC to IOC Doc 29 at pressing.

Why is my olive oil cloudy?

Either it is unfiltered and the cloudiness is fruit particles and water, or it has been refrigerated or left somewhere cold and the fats have partly solidified. Cold cloudiness clears at room temperature. Unfiltered cloudiness settles into sediment over time, and that sediment should be left in the bottle, not poured.

How long does unfiltered olive oil last?

At its best for a couple of weeks after pressing. It stays technically usable for months, but the flavor flattens and defects develop much sooner than in filtered oil. If you buy it, buy it fresh and use it quickly.

Is cloudy olive oil a sign of quality?

No. Cloudiness tells you the oil was not filtered. It tells you nothing about the fruit, the harvest date, the acidity, or the polyphenols. Some of the worst oils are cloudy and some of the best are clear.

Does Heraclea sell unfiltered olive oil?

No. Every bottle is filtered the day it is pressed and stored under nitrogen until it ships, because we want the oil to taste the way it did at the mill when you open it months later. If we ever release an olio nuovo, it will carry the pressing date and a two-week clock.

Keep reading

• Cold Pressed Olive Oil: What It Actually Means, From the Press Floor
• Does Olive Oil Go Bad? How Long Olive Oil Lasts
• High Polyphenol Olive Oil: What the Number Means
• Turkish Olive Oil: The Complete Guide, From a Producer in Milas

Berk Bahceci, Co-Founder