Making Olive Oil: How Olives Become Extra Virgin Oil
Making olive oil is, at its heart, a race against the clock. An olive begins changing the moment it leaves the tree, and every hour between branch and press costs the oil a little of its flavour, freshness, and delicate compounds. The basic process has not changed in thousands of years — pick the fruit, crush it, separate the oil — yet within those three steps live all the decisions that separate a vivid, peppery extra virgin from a flat, anonymous oil. This article walks through how olive oil is actually made, stage by stage: the harvest and why its timing matters so much, milling and malaxation, what "cold-pressed" really means (and the truth about "first press"), and the final choices around filtering and bottling that decide how the oil reaches your kitchen.
For our own oil, see our cold-pressed organic Marrakech olive oil.
The Short Answer
- Olive oil is made in three essential stages: harvesting the fruit, crushing it into a paste, and separating the oil — ideally all within hours.
- Harvest timing shapes the oil: earlier picking gives greener, more peppery, polyphenol-rich oil; later picking gives milder, softer oil and more of it.
- "Cold-pressed" means the paste is kept below about 27°C during extraction, protecting flavour, aroma, and polyphenols from heat damage.
- "First press" is mostly a romantic leftover — modern mills extract in a single pass; the term that actually matters today is extra virgin.
- Speed is the quality secret: olives pressed within hours of picking make fresh oil; olives that sit for days make defective oil that must be refined.
- The final choices — unfiltered or filtered, and dark glass bottling — decide how much of the mill's freshness survives to your kitchen.
The Harvest: Where the Oil Is Really Decided
Everything that matters about an olive oil is set in motion before the fruit reaches the mill. Olives ripen from bright green to purple-black through the autumn, and the picking date is the producer's single biggest stylistic decision. Pick early, while the fruit is still green, and you get less oil per tree but a livelier one — grassy, bitter, peppery, and rich in the polyphenols that give extra virgin its character and its research interest. Pick late and the yield rises while the flavour mellows and the polyphenols fade. Neither is wrong; they are different oils.
How the fruit comes off the tree matters too. Hand-picking and small rakes keep the fruit intact; heavily mechanised harvesting is faster but bruises more fruit — and a bruised olive starts oxidising and fermenting immediately. This is also where the race begins: once picked, olives should reach the mill within hours, not days. Fruit left in heaps overnight warms up and ferments, producing the musty defects no later step can remove. The world's best producers press the same day — often within hours — of picking.
Milling and Malaxation: From Fruit to Paste
At the mill, the olives are cleaned of leaves and twigs, washed, and crushed whole — stone and all — into a thick, dark paste. Traditional mills used granite stone wheels; modern mills use stainless-steel crushers that do the same job faster and with less exposure to air. Romantic as the stone wheel is, the steel crusher often makes fresher oil precisely because it is quicker.
Then comes the step most people have never heard of: malaxation. The paste is slowly churned for thirty to sixty minutes, which coaxes the microscopic droplets of oil to find each other and merge into larger drops that can be separated. It is a balancing act — longer, warmer malaxation frees more oil but sacrifices aroma and polyphenols, while shorter, cooler malaxation keeps the oil vivid at the cost of yield. Here, again, quality and quantity pull in opposite directions, and every producer chooses a side.
Extraction: What "Cold-Pressed" Actually Means
The oil now has to be separated from the water and solids. Traditionally this meant stacking the paste on woven mats and squeezing it in a press — the origin of "first press". Modern mills instead feed the paste through a centrifuge: a horizontal decanter spins it at high speed, and oil, water, and solids part ways by density. The oil that emerges is, quite literally, fresh fruit juice.
"Cold-pressed" (or cold-extracted) has a precise meaning: the paste is kept below about 27°C throughout. Heat would free more oil — warm paste flows more easily — but it strips aroma and degrades polyphenols, so staying cold is a deliberate sacrifice of yield for quality. "First press", by contrast, is mostly a historical leftover: modern centrifuges extract in a single pass, so virtually every extra virgin oil today is by definition from the "first" and only extraction. The phrase that carries real legal weight now is extra virgin: mechanically extracted, no heat damage, no chemicals, low acidity, and zero sensory defects.
Settling, Filtering, and the Unfiltered Question
Straight from the centrifuge, new oil is cloudy — alive with tiny fragments of olive flesh and droplets of fruit water in suspension. The producer now chooses: filter the oil bright and clear, or leave it unfiltered and let the sediment settle naturally in the bottle or tank.
Filtering gives a cleaner look and can extend shelf stability. Leaving the oil unfiltered keeps it closer to how it left the press — fuller-textured, with fine natural sediment that drifts to the base of the bottle over time. That sediment is simply fruit; it is harmless and, to many, a mark of a minimally processed oil. An unfiltered oil is best enjoyed young, which suits oils made in small seasonal batches and sold fresh rather than warehoused.
Bottling: Protecting What the Mill Made
The final stage is the quietest but still matters: getting the oil into a container that defends it. Light is one of olive oil's great enemies — it drives the oxidation that turns fresh oil stale — which is why serious producers bottle in dark glass or tins, never clear plastic. The oil is stored cool, away from oxygen where possible, and ideally sold within months of pressing rather than years. From here, the responsibility passes to your kitchen: a cool dark cupboard, a tightly closed cap, and a bottle finished while it is young. Everything the harvest and the mill achieved can be preserved or squandered in this last stretch — and choosing well at purchase is most of the battle, as we cover in our guide to choosing a quality olive oil.
Why Sidr & Stone
If this article has a single lesson — that great olive oil is made by harvesting carefully and pressing fast and cold — then it is fair to say how our own oil is made.
- Single-estate — one family-owned grove on the plains outside Marrakech, Morocco; no blending across origins.
- Rain-fed — no irrigation; the trees take what the season gives.
- Organically grown — no synthetic fertilisers, pesticides, or herbicides.
- Single harvest — a small, limited batch; once the season's pressing is gone, it is gone until next year.
- Cold-pressed within hours of harvest — flavour, aroma, and polyphenols preserved.
- Unfiltered extra virgin — minimally processed, and may show natural sediment.
- 100% natural — a single ingredient, nothing added.
- Dark glass with a gold label — protective packaging against light.
- Halal certified.
- 10% of profits to charity — Sidr & Stone's brand-wide commitment.
- Fulfilment in the UK, EU, and US.
We will not tell you Sidr & Stone is the best olive oil — that is not our claim to make. What we will say is that every step described above — the same-day cold pressing, the unfiltered bottling, the dark glass — is how our single small batch is made each season, and the evidence of that care is in the taste and the colour of the oil itself.
Frequently Asked Questions
How is olive oil made, step by step?
Olives are harvested, washed, and crushed whole into a paste; the paste is slowly churned (malaxation) to gather the oil droplets; the oil is then separated by press or centrifuge, left to settle or filtered, and bottled — ideally all within hours of picking.
What does cold-pressed olive oil mean?
It means the olive paste is kept below about 27°C during extraction. Heat would yield more oil but damages flavour, aroma, and polyphenols — cold extraction sacrifices quantity for quality.
Is "first press" better than cold-pressed?
"First press" is largely a historical term — modern mills extract in a single pass, so there is no second pressing. The meaningful markers today are "extra virgin" and "cold-pressed/cold-extracted".
How long after harvest should olives be pressed?
The sooner the better — ideally within hours, and certainly within a day. Olives that sit in heaps warm up, ferment, and develop defects that disqualify the oil from extra virgin grade.
How many olives does it take to make a bottle of olive oil?
Very roughly, it takes around 5–7 kilograms of olives to make one litre of oil, depending on variety, ripeness, and season — a 500ml bottle represents the fruit of a small tree's whole year.
What is the difference between filtered and unfiltered olive oil?
Filtered oil has its fine fruit particles removed for clarity and shelf stability; unfiltered oil keeps them, giving a fuller texture and natural sediment. Unfiltered oil is closest to how the oil left the press and is best enjoyed young.
Can you make olive oil at home?
In small amounts, yes — crushing olives and working the paste by hand — but it is laborious and the yield is tiny. Quality oil really needs a mill's speed and temperature control, which is why even small growers take their fruit to a local press.
Is olive oil a medicine?
No. Olive oil is a food, not a medicine. It has a long traditional history — including being honoured in the Prophetic Sunnah — and a substantial body of modern research, particularly around polyphenols, cardiovascular health, and the Mediterranean diet pattern. It can be a worthwhile part of a healthy routine, but it does not cure diseases and is not a substitute for medical care. Be cautious of any olive oil marketed with specific disease-cure claims.
Final Thoughts
Making olive oil is simple to describe and hard to do well: pick good fruit at the right moment, crush it fast, keep it cool, and protect the result from light and air. There is no secret machine and no shortcut — only a long chain of small decisions where quality and quantity pull in opposite directions, and the producer chooses, again and again, which one to serve.
That is worth remembering at the shelf. When a bottle tells you its harvest date, its estate, and how it was pressed, it is showing you those decisions. When it tells you nothing, that is a decision too. The story of how an oil was made is the most honest quality label there is — better than any slogan on the front.
Our cold-pressed organic Marrakech olive oil — single-estate, rain-fed, and pressed within hours of harvest — is available to pre-order now, with fulfilment in the UK, EU, and US.
Pre-Order Sidr & Stone Organic Marrakech Olive Oil — Limited First Harvest →
Disclaimer: This article describes general production methods and product information at the time of writing; practices vary by producer and details may change. Olive oil is a food, not a medicine, and is not a substitute for medical treatment of any condition. For any health concern, consult a qualified medical professional.
