It began in my grandmother's kitchen in Sparta.

Every summer of my childhood, I spent three months in Sparta, in my grandparents' house. I remember the stark, "Spartan" ways, and the silence of that home. I did not speak good Greek then, and language was a clear barrier between us.

I spent my days cycling in the garden, running after the chickens, and wandering amongst the olive trees. And when I grew bored, I would peek into the semi-dark kitchen backroom, where my grandmother stood for hours, preparing food and marinating olives.

The smell of olive oil and olives was overpowering. Intoxicating. Inebriating. My yiayia would stay in that room until it was lunchtime, when she would call us all to sit.

The sight of the table was unbelievable: covered with Greek delicacies, homemade food bringing us all together. And there, something magical happened. A flow of conversations, sounds, smells and tastes would fill our home, in striking contrast to the rest of the day.

For me, Nikkitas is that feeling. A connection to my roots, and a complete awakening of the senses.

The hands that came before mine

My family has looked after our olive groves, inherited from one generation to the next, for five generations, alongside our beekeeping. The groves sit among the ruins of Ancient Sparta, at the foot of Mount Taygetos, flanked by the Eurotas river, a stone away from King Leonidas' tomb, and close to the UNESCO-listed town of Mystras.

Behind every bottle is the weight of generational care for the olive trees all around our village: the hard work of getting to difficult groves and fields, and carrying hundreds of baskets.

We work the traditional way, respectful of our great-grandparents' ways. Careful pruning, composting, and no machines, which builds the organic matter in the soil and keeps both the groves and the trees healthy.

Around Sparta the ground is well-drained, sandy and stony; the summers are hot and dry, the winters mild and wet. It is what the olives have always wanted.

Five generations later, rooted in tradition

We do not use any machines to collect the olives. We know the metal has a negative impact on the fruit, so we pick everything by hand. Very few producers do that, because it takes far longer. Hand-picking also prevents bruising, and a bruised olive begins to ferment before it ever reaches the press.

What we pick, we press on-site within 24 hours. We are a small operation: about five of us for most of the year, seven at the busiest point of the harvest, plus two or three beekeepers.

We own the mill, the processing facility and our own laboratory, and every batch is tested for polyphenols and acidity before it is bottled.

When I go to the factory with my children, they fall silent. They drink in the noise of the machines, the sound of the olives going through the line, and the overwhelming smell of olive oil. It is the same when they walk through the groves. The body remembers the generations past.

Three olives, and why we never chose just one

Most growers harvest a single variety; it is easier, and it pays sooner. We tackle three, tripling the work and the love, because each one brings something the others cannot.

• Koroneiki. Hardy and forgiving, the smooth and steady base of everything we make.
• Athinolia. Rare, grown almost nowhere but our own land. The trees are difficult and ask for far more care than they should, and give back the most elegant, complex, fruity aromas in return.
• Koutsourolia. The old heritage olive that legend says once crowned the victors at the Games. It clings to the steepest, hardest ground, where only a person, never a machine, can reach it.

Keeping all three alive is its own quiet act of stubbornness. It keeps olives growing in soil the rest of the world has given up on.

You can taste all three in a single spoonful. The Koroneiki arrives first, vivid and green, like fresh-cut grass. Then the Koutsourolia rounds it out, soft and gently fruity. And right at the end the Athinolia lifts, elegant, with a clean peppery warmth that catches at the back of the throat.

Golden-green in the glass, full on the tongue, and it lingers long after the bread is gone.

Why we test every batch

All of that work has a name: polyphenols. They are the natural compounds behind a real extra virgin's peppery kick, and they are what most people are really reaching for when they look for a good oil.

Polyphenols are valued for their antioxidant and anti-inflammatory properties. The EU permits just one carefully worded health claim for them: that olive oil polyphenols contribute to the protection of blood lipids from oxidative stress. They are also fragile, the first thing to fade when an oil is rushed, heated or carelessly handled.

A typical supermarket extra virgin holds around 50mg per kilo. The EU recognises that claim once an oil passes 250mg per kilo. Ours is tested at 700mg per kilo, at a free acidity of just 0.25%, and we test every batch ourselves, in our own laboratory.

And here is what saddens me. So much of the oil sold today is sold the other way around. Not long ago I came across a thirty-minute video of a doctor online, endorsing and selling olive oil. One of those bottles was £50 for 250ml. That is £20 per 100ml! It had never been tested, and there was no real way to verify where it had come from. I did not know whether to laugh or cry.

It feels as though olive oil has become a marketing game. When the friends behind The Fine Source first told me that roughly three in four bottles, about 73% of imported extra virgin, do not live up to the standard they are sold under, I did not want to believe it. Watered down with cheaper oils, blended across countries, the label saying one thing and the bottle holding another.

In my family that is simply unthinkable. A lot of producers buy from Greece and label it Italian, for example. Or they blend various oils from various countries together, diluting the purity and the product, cheating the system for profit. We have never done it, and we never will.

Ours is one family, one valley, one oil. We will tell you anything you want to know about it, because there is nothing in it we would ever need to hide. A number you cannot verify is only a number, and a provenance you cannot trace is only a story.

One honest word, though: do not chase polyphenols for their own sake. Too high, and an oil turns harsh and bitter, not something you would want every day. We simply wanted an oil you would happily reach for at every meal, one that is tested and true, and that gives you the benefits a genuinely high-polyphenol olive oil is meant to bring.

What we give back

Working this way does more than make better oil. The care we take, and the fact that we use no machines, steadily builds the organic matter in our soil. That improves its fertility and our trees' health, and it means our olive trees help store carbon, in the ground and in the trees themselves.

Nothing is wasted. Our olive by-product either feeds the goats, sheep and cows, or goes to energy and fertilisation, with about 80% used for composting and 20% returned directly to the fields. Our glass bottles and jars are responsibly sourced and infinitely recyclable, and we are proud to use 100% recyclable packaging.

We also support a community of very small artisan producers around us, gathering the fruit of hundreds of tiny neighbouring family groves and fields, all keeping the same respect for the traditional ways in the fertile, wild lands of Sparta.

And we have partnered with Desmos, a non-profit foundation, to support local schools in Sparta with educational equipment and supplies.

How a private family oil became something to share

For most of my life, none of this was for sale. The oil, the olives, the honey were for the people we loved, the way they had always been.

Then, in 2017, I found myself at dinner at L'Atelier de Joël Robuchon, at the time a Michelin-starred restaurant in London. The chef wanted me to try an olive oil he had just discovered from Spain, and I could not help myself: I told him my own family made a rather good one.

He was curious, and asked me to bring it the next day. When I came back he was waiting with a professional buyer; they tasted the oil, the olives and the honey, loved all of it, and advised me to create proper packaging for the products.

Until then, we had never thought of selling anything. And that is how it all began.

How it finds its way to you

The Fine Source came later, and gently. It was started by three friends here in London who love food the way we do: long dinners that run late, cooking for the people they love, and the simple pleasure of finding something remarkable and wanting to share it at once.

Their frustration was one I understood immediately. The real things, the oil poured at a little trattoria, the honey on a breakfast table in the Peloponnese, were almost impossible to buy once you were home again. They believed the answer was just as simple: go to the source. Understand where something comes from, how it was made, and by whom.

So that is what they do. Every product they carry is traceable to its producer. They visit, they taste, they verify, and they choose only what they would happily serve at their own table. Something small and careful, with no filler, no shortcuts, and no compromise.

I said yes for two reasons. The first was the people. We met through our children, who play basketball together, and I could see they valued the personal side of all this as much as I do: the sharing of a story, and the carrying of our name the way we would carry it ourselves.

The second was honest and practical. To bring what we make to more tables, through all the new hurdles of trading across borders, I needed a partner I could trust completely. In them, I found one.

The bottle they bring you is all glass, with the name printed straight onto it. No label to peel away, nothing hidden. The lid is glass too, meant to be kept and used again, and the small red mark is the shield the old Spartans carried.

It was made to stand out on the table, in the middle of everything, the way good oil always did in my grandmother's house. You can buy it here in the UK now, or come and taste it first at their tasting room, 92 York Street, in London.