27°C: The Number Behind Every Drop of ORO CELESTE

One Temperature Changes Everything

Among all the terms printed on an extra virgin olive oil label, 'cold press' and 'cold extraction' are among the most frequently seen — and least thoroughly understood. The underlying principle is straightforward: the temperature maintained during malaxation, the stage where the olive paste is kneaded before oil is separated, is one of the most consequential decisions a producer makes.

Under EU Regulation EC No 1513/2001 and its subsequent amendments, the 'cold extraction' designation is only permitted when the paste temperature does not exceed 27°C at any point during processing. This is not an arbitrary figure. According to data published by the International Olive Council (IOC), the loss of volatile aroma compounds accelerates and oxidation of heat-sensitive polyphenols speeds up once the paste temperature climbs beyond that threshold.

What Happens When the Temperature Rises

Raising the pressing temperature increases yield — more oil from the same weight of olives — which makes it an economically attractive option for producers. The trade-off, however, is paid in quality.

A study published by researchers at Spain's National Research Council (CSIC) found that when pressing temperature rose from 27°C to 35°C, concentrations of volatile compounds responsible for fresh, grassy, and fruity character — including hexanal and other C6 aldehydes — fell by as much as 30–40%. These are precisely the compounds that produce the distinctive green notes in freshly pressed olive oil. As temperature climbs, the aroma profile tends to flatten toward a neutral, undifferentiated character.

Polyphenol loss is equally significant. Researchers at the University of Bologna reported that raising malaxation temperature from 20°C to 30°C produced a measurable reduction in key phenolic compounds, including oleocanthal and oleacein. Polyphenols are directly linked to the bitter and pungent attributes of the oil, and also contribute to its oxidative stability.

Why ORO CELESTE Holds to 27°C

ORO CELESTE presses its Andalusian olives on the day of harvest or within 24 hours, and maintains a below-27°C temperature across every stage of the process. The decision trades yield for the preservation of aroma and phytochemical content.

The figures across the product range reflect that choice. Ojiblanca records an acidity of 0.16% and polyphenol content above 600 mg/kg. Sibarita comes in at 0.14% acidity and above 500 mg/kg polyphenols. Picual reaches 0.20% acidity and above 800 mg/kg polyphenols. Picual is already recognized as a cultivar with an inherently high polyphenol potential; cold pressing at this temperature is understood to maximize what the fruit can deliver.

Maintaining 27°C while still allowing sufficient malaxation time is a genuine technical challenge. Lower temperatures raise paste viscosity, which means oil droplets coalesce less readily and overall yield falls. ORO CELESTE accepts that trade-off on the basis that fewer liters per tonne of olives means greater flavor density per bottle.

What the Drinker Tastes: Flavor Profile

In the vocabulary used by professional EVOO tasters, cold-pressed oils produced below 27°C tend to express fruity, grassy, peppery, and bitter attributes with greater clarity and intensity.

Ojiblanca leads with ripe apple and almond sweetness, followed by a lingering peppery finish. Sibarita is the most balanced of the three cultivars — artichoke notes sit alongside a measured, soft bitterness. Picual is the most assertive: tomato leaf, cut grass, and black pepper layer together, with the high polyphenol content expressed directly in the flavor.

This complexity is difficult to preserve at elevated pressing temperatures. According to the IOC's sensory evaluation standards, extra virgin classification requires that positive attributes — fruitiness, bitterness, and pungency — all be perceptible. When temperature control is relaxed, all three characteristics tend to weaken simultaneously, and maintaining the grade itself becomes harder to achieve.

Temperature, Acidity, and Storage

Pressing temperature also bears on initial acidity — the free fatty acid content that must fall below 0.8% for extra virgin classification, though genuinely high-quality oils are typically managed at 0.3% or below. Academic literature has reported that cold pressing may contribute to lower free fatty acid formation by limiting lipase enzyme activity during extraction, though it is too early to draw firm conclusions about the scale of this effect across different production contexts.

The same logic carries into storage. Higher polyphenol content and lower initial acidity are associated with greater oxidative stability, and when combined with correct storage conditions — away from direct sunlight and heat — may help the oil hold its character for longer. Once opened, storage in a cool, dark location and consumption within two to three months is the generally accepted recommendation.

The '27°C cold press' line on a label, then, is more than marketing copy. It is a record of temperature — a measure of how much was preserved between the olive on the tree and the oil in the bottle.