From plant to bottle: how extra virgin olive oil is produced | Olio Limera
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From plant to bottle: how extra virgin olive oil is produced
Understanding how extra virgin olive oil is made helps you make better choices. In this practical guide, we clearly examine all the stages: harvesting , pressing , malaxation , cold extraction , filtration , and storage . This is where the sensory profile, polyphenol content, and final quality are determined.
The oil cycle: the phases that really matter
- Harvest (controlled ripening, healthy olives)
- Transport (ventilated boxes, tight deadlines)
- Defoliation and washing
- Crushing (breaking of the pulp)
- Coalescence (coalescence of oil droplets)
- Cold extraction (oil/water/solid separation)
- Filtration (stability, clarity)
- Storage (stainless steel, nitrogen, darkness)
- Bottling (dark bottles, anti-refill caps)
Harvesting: Times and methods that make the difference
The harvest window extends from true veraison to the desired ripeness. Too unripe olives: low yield but high polyphenols; too ripe: high yield but flat flavor profile. Two approaches:
- Manual/selective : slower, ideal for top quality and delicate cultivars.
- Facilitated/mechanical : shakers and nets; high quality if times are quick.
Rule of thumb: Process the olives within 12–24 hours of harvesting. Avoid closed bags: they encourage fermentation and defects (heating, winey).
Crushing and malaxing: where the aroma is built
Crushing breaks the drupe. The type of crusher (hammer, disc) influences the bitterness/spiciness and greenness. During malaxation, the paste is stirred for 15–40 minutes: this is where the microdroplets coalesce.
| Phase | Key parameter | Recommended range | Impact on quality |
|---|---|---|---|
| Kneading | Time | 15–30 min | More aroma, watch out for oxidation |
| Kneading | Temperature | 24–27°C | Preserves volatiles and polyphenols |
| Extraction | Pasta temperature | ≤ 27°C | “Cold” according to the norm |
Extraction: What does "cold pressing" really mean?
Cold extraction means that the oil is obtained at process temperatures ≤ 27°C . For the consumer, this means: better preservation of green aromas , higher polyphenol content, and less oxidation. Modern decanter systems (two or three phases) separate oil, water, and pomace: a clean process, stable yields, and fewer defects.
Filtration: why you should do it (now)
Filtering eliminates microparticles and wastewater that accelerate hydrolysis and rancidity. Unfiltered oil may be initially pleasant but is less stable . Early filtration (using screens or membranes) improves shelf life and clarity.
Storage and preservation: quality must be protected
- Temperature-controlled stainless steel tanks (14–18°C)
- Inert with nitrogen to reduce contact with oxygen
- Dark and cool : light and heat degrade aromas and vitamin E
- Bottling in dark glass or can, with anti-oxygen caps
Pro tip for home: Always close the bottle, avoid near fires, and consume within 4–6 weeks of opening.
Olive Oil Acidity: How to Read It (and Why You Can't Taste It)
Free acidity (expressed as oleic acid) measures the degradation of triglycerides. To be considered extra virgin, it must be ≤ 0.8%. You can't "taste" it; you can read it on the label or the technical data sheet. Very low values often indicate healthy olives and a rapid, careful processing.
How to choose a real extra virgin olive oil
- Clear origin and indicated harvest (campaign or month)
- Cold pressing and filtration declared
- Sensory notes : balanced fruity, bitter and spicy
- Storage : dark bottle, batch and shelf life clearly visible
The Limera method in 5 points
- Harvested at the right level of ripeness and processed quickly
- Temperature control during crushing/kneading (≤ 27°C)
- State-of-the-art decanter extraction
- Early filtration for stability and clarity
- Storage in steel, nitrogen and bottling in dark glass
