Pesto Oil: Which Olive Oil to Use for Pesto
"Pesto oil" can mean a couple of things, and it is worth pinning down which you are after. Most often it refers to the olive oil that goes into pesto — the ingredient that binds the basil, pine nuts, garlic, and cheese into a sauce — and the question is really which oil to use. Sometimes it means a thin, drizzleable basil-and-oil blend used as a finishing oil in its own right. Either way, the oil does more work than people realise: it carries the flavour, sets the texture, and largely determines whether the result tastes fresh and green or flat and greasy. This article explains what "pesto oil" means, why the choice of olive oil matters so much, and how to use it well.
For our own oil, see our cold-pressed organic Marrakech olive oil.
The Short Answer
- "Pesto oil" usually means the olive oil used to make pesto. Traditional Genovese pesto is built on good extra virgin olive oil, which binds the sauce and carries its flavour.
- It can also mean a basil-infused finishing oil. A thin blend of olive oil and basil (and sometimes garlic) used to drizzle over dishes — looser than a full pesto.
- The oil's quality really matters here. Because pesto is raw and uncooked, the oil's flavour comes through directly; a flat or rancid oil makes a flat pesto.
- Use a good extra virgin oil, raw. Pesto isn't heated, so all the polyphenols and aroma of a fresh extra virgin oil survive to the plate.
- Balance is the trick. A very intense, peppery oil can overwhelm delicate basil; a fresh, well-balanced extra virgin oil is usually the safest choice.
- Sidr & Stone's olive oil is single-estate Moroccan, rain-fed, organically grown, and cold-pressed unfiltered within hours of harvest — the kind of fresh oil that makes a good raw sauce.
What "Pesto Oil" Actually Means
There is no official product called "pesto oil", which is why the term is slightly slippery. In practice it points at one of two things.
The first, and most common, is simply the olive oil you use to make pesto. Classic pesto alla Genovese is an emulsion of fresh basil, pine nuts, garlic, hard cheese (Parmigiano and Pecorino), salt, and a generous quantity of good olive oil. The oil is not a minor seasoning here — it is a primary ingredient, often a third or more of the sauce by volume, and it does the structural work of binding everything into a smooth, spoonable paste. When people search for "pesto oil", they usually want to know which oil belongs in that recipe.
The second meaning is a basil-infused finishing oil: a thinner, more pourable blend of olive oil with basil (and sometimes garlic or other herbs), used to drizzle over pasta, soup, grilled vegetables, or bread. It is pesto's looser cousin — less of a sauce, more of a flavoured oil — and it leans even more heavily on the quality of the base oil, since there is less else going on.
In both cases the lesson is the same: the olive oil is doing a great deal of the flavour work, and because nothing is cooked, there is nowhere for a poor oil to hide.
Why the Olive Oil Matters So Much in Pesto
Pesto is one of the most unforgiving uses of olive oil, in the best sense: it shows you exactly what your oil tastes like. There are three reasons the choice matters more here than in, say, a slow-cooked stew.
It is raw. Pesto is never cooked — at most it warms slightly against hot pasta — so the oil's flavour reaches you undimmed. The grassy, fruity, peppery notes of a fresh extra virgin oil come straight through; equally, the dull or rancid notes of a tired oil come through just as clearly. Heat can mask a mediocre oil; a raw sauce cannot.
It is a large proportion of the dish. Because the oil is a primary ingredient rather than a splash, its character is front and centre. A great oil lifts the whole sauce; a flat refined oil leaves it greasy and lifeless however good the basil is.
It carries the other flavours. Fat is the vehicle for aroma, and the oil literally carries the scent of basil and garlic to your nose and palate. A clean, flavourful oil delivers those aromatics beautifully; a heavy or off oil muddies them.
This is why traditional Italian cooks are particular about the oil in pesto, and why "any oil will do" is poor advice here even when it is fine elsewhere.
Which Olive Oil to Use for Pesto
The right answer is a good, fresh extra virgin olive oil — but with one balancing consideration worth understanding.
Use extra virgin, not refined. Oils sold as "pure", "classic", or "light" are refined and largely flavourless; in a raw sauce that depends on the oil for taste, they give you greasiness without character. Extra virgin oil keeps its flavour and its polyphenols, both of which you want in a pesto.
Then think about intensity. Extra virgin oils range from mild and buttery to robust and aggressively peppery. Basil is a delicate herb, and a very intense, bitter, high-polyphenol oil can overwhelm it, throwing the sauce out of balance. Many cooks therefore choose a fresh extra virgin oil that is flavourful but well-balanced — green and lively without being harsh — so the oil supports the basil rather than fighting it. If your oil is very robust, you can use a little less of it, or pair it with a milder one, to keep the basil in the lead.
Freshness, as always, is part of quality: a recent harvest, dark glass, and a named origin point to an oil that still has its aromatic life. That liveliness is exactly what a good pesto needs.
How to Use Pesto Oil Well
Whether you are making a full pesto or a looser basil finishing oil, a few habits get the best from the oil.
For a traditional pesto, add the oil raw and at the end — pound or blend the basil, nuts, garlic, and cheese first, then work in the oil to bind, rather than heating any of it. When tossing pesto through pasta, take the pan off the heat and let it cool for a moment first; fierce heat can dull the oil's fresh notes and turn the basil drab. A spoonful of the starchy pasta water helps the sauce cling without needing to cook it.
For a basil finishing oil, blend a handful of fresh basil with a good extra virgin oil (and a little garlic if you like), strain if you want it clear, and drizzle it raw over finished dishes. Make it in small batches and use it quickly, since fresh herb oils do not keep long. As with pesto, the oil is most of the flavour, so a fresh extra virgin one is worth using.
For a fuller walkthrough of choosing a good oil, see our guide to choosing a quality olive oil.
Why Sidr & Stone
A raw sauce like pesto is the clearest test of an olive oil there is — it rewards a fresh, characterful extra virgin oil and exposes a tired one. That is precisely the kind of oil we set out to make.
- Single-estate — one family-owned grove near 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 — small, limited batch; once the season's pressing is gone, it's gone until next year
- Cold-pressed within hours of harvest — flavour, aroma, and polyphenols preserved
- Unfiltered extra virgin — minimally processed, may show natural sediment
- 100% natural — single ingredient, no additives
- Dark glass with gold label — protective packaging against light
- Halal certified
- 10% of profits to charity (brand-wide commitment)
- Fulfilment in the UK, EU, and US
We will not tell you Sidr & Stone is the best olive oil — that would be the very kind of bare claim a careful cook should distrust. What we will say is that our oil is single-estate Moroccan, rain-fed, organically grown, and cold-pressed within hours of harvest — and that the evidence of that care is in the taste, the colour, and the season's small limited batch.
Frequently Asked Questions
What is pesto oil?
Usually it means the olive oil used to make pesto, which is a primary ingredient that binds and flavours the sauce. It can also mean a basil-infused finishing oil — a thinner blend of olive oil and basil used to drizzle over dishes.
What kind of olive oil is best for pesto?
A fresh, good-quality extra virgin olive oil. Because pesto is raw, the oil's flavour comes through directly. Choose a flavourful but well-balanced extra virgin oil rather than an aggressively peppery one, so it supports the delicate basil rather than overwhelming it.
Can I use regular or "light" olive oil for pesto?
You can, but it's not recommended. "Regular", "pure", "classic", and "light" oils are refined and largely flavourless, so in a raw sauce that depends on the oil for taste they give greasiness without character. Extra virgin is the better choice.
Why does my pesto taste bitter or harsh?
Often it's the oil. A very robust, high-polyphenol extra virgin oil can taste bitter and overwhelm basil, and over-blending can also make the oil taste bitter from the friction and heat of the blade. Use a balanced oil, blend gently, and don't overdo the quantity.
How do I make a basil finishing oil?
Blend a handful of fresh basil with a good extra virgin olive oil (and a little garlic if you like), strain if you want it clear, and drizzle it raw over pasta, soup, or vegetables. Make small batches and use them quickly, as fresh herb oils don't keep long.
Should I heat pesto?
No — pesto is best used raw or just warmed by hot pasta. Take the pan off the heat before tossing it through, and use a little pasta water to loosen the sauce. Fierce heat dulls the oil's fresh notes and turns the basil drab.
Does the olive oil really make a difference in pesto?
Yes, a large one. The oil is a primary ingredient in a raw sauce, so its flavour is front and centre. A fresh, characterful extra virgin oil lifts the whole pesto; a flat or rancid oil leaves it greasy and lifeless however good the basil is.
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
"Pesto oil" is really a reminder of how much the olive oil matters in any uncooked dish. In pesto, the oil is not a background seasoning but a leading ingredient — raw, plentiful, and carrying the basil and garlic to your palate — so its quality shows up directly on the plate. Use a fresh, balanced extra virgin oil and the sauce tastes green and alive; use a flat refined one and no amount of good basil will save it.
The practical takeaway is simple: treat the oil in your pesto with the same care as the basil. Choose a good extra virgin oil, keep it fresh, use it raw, and let it do the considerable work it is so well suited to.
Our cold-pressed organic Marrakech olive oil is made for exactly this kind of raw, flavour-first use — single-estate, rain-fed, unfiltered, and pressed within hours of a patient harvest — and is available now for pre-order, with fulfilment in the UK, EU, and US.
Pre-Order Sidr & Stone Organic Marrakech Olive Oil — Limited First Harvest →
This article describes general culinary uses of olive oil in pesto at the time of writing; recipes and preferences vary. 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.
