Sub-Zero Extraction: The Science Behind the World's Healthiest Olive Oil
What Is Sub-Zero Extraction?
Sub-zero extraction — also called Extra Cold Extraction — is a revolutionary olive oil production method that crushes and presses olives at temperatures below 0°C. Frantoio di Montalcino is the first olive mill in the world to implement this process at an industrial scale, producing extra virgin olive oils with polyphenol concentrations of up to 1,200 mg/kg.
Why Temperature Matters in Olive Oil Production
Traditional cold-pressed olive oil is extracted at temperatures below 27°C — already a significant step above ambient industrial processing. But heat, even mild heat, degrades the most fragile and valuable compounds in fresh olive oil: polyphenols, antioxidants, and vitamin E. These bioactive molecules are responsible for the characteristic peppery finish of high-quality EVOO, and more importantly, for its extraordinary health properties.
By dropping extraction temperatures below zero, Frantoio di Montalcino preserves a far higher concentration of these compounds than any conventional cold-press method can achieve.
The Science: Oxford University & University of Perugia
The Extra Cold Extraction method was developed in collaboration with Oxford University and the University of Perugia, under the guidance of Professor Maurizio Servilli — one of the world's foremost authorities on olive oil chemistry and polyphenol biology. The process has been independently certified, with polyphenol levels in our BRUNERA line verified at up to 1,200 mg/kg — among the highest ever recorded for a commercially produced extra virgin olive oil.
For context, the EU health claim threshold for high-polyphenol olive oil is 250 mg/kg. BRUNERA contains nearly five times that amount.
The Benefits of High-Polyphenol EVOO
Polyphenols are powerful natural antioxidants. In olive oil, the primary polyphenol responsible for health effects is oleocanthal — a compound with anti-inflammatory properties comparable to ibuprofen, studied extensively for its potential role in cardiovascular health, cognitive function, and longevity. Sub-zero extraction preserves significantly more oleocanthal and related compounds than any other extraction method.
- Cardiovascular protection — high polyphenol EVOO is associated with reduced LDL oxidation and improved arterial elasticity.
- Anti-inflammatory effects — oleocanthal inhibits the same enzymes targeted by NSAIDs.
- Longer shelf life — the antioxidant compounds act as natural preservatives, keeping the oil fresher for longer.
- Richer flavour — the peppery, bitter notes that polyphenols create are hallmarks of truly fresh, high-quality EVOO.
Our Master Miller: Daniele Lepori
The Extra Cold Extraction process is only as good as the hands that oversee it. At Frantoio di Montalcino, that is Daniele Lepori — 25 years of experience, 86 international gold medals, and consecutive recognition in the Flos Olei guide, which ranks the top 500 olive oils in the world. In 2021, Daniele was named Flos Olei "Best Medium Fruity" in the World.
Every bottle of BRUNERA is an expression of this combination: pioneering technology and irreplaceable human expertise.
The Only Frantoio Within the Brunello di Montalcino Appellation
Location is everything in olive oil, just as in wine. Frantoio di Montalcino sits within the Brunello di Montalcino appellation in southern Tuscany — a microclimate defined by altitude, clay-limestone soils, and warm days offset by cool nights. These conditions stress the olive trees naturally, pushing them to produce fruit with higher polyphenol density. Combined with sub-zero extraction, the result is an olive oil that is genuinely unlike anything else in the world.