The Ayvalık Olive Oil designation of origin: the chemical profile in the certificate

Geographical indication certificates are usually full of phrases like "characteristic of the region". Ayvalık Olive Oil's is not — it contains three tables setting out, in figures, the chemical ranges within which an oil may carry the name.

The record

The product definition is a single sentence: extra virgin olive oil obtained from Ayvalık cultivar olives grown in the Ayvalık district and picked at early or ripe harvest.

Three constraints sit in that sentence: place, cultivar and grade. All three bind.

Quality limits

Acidity of ≤0.8% is already the legal ceiling for extra virgin; the certificate does not go below it but holds the peroxide value at 18. We explained what acidity means separately.

Fatty acid and sterol profile

This is the distinctive part of the certificate — whether an oil is Ayvalık can be tested in a laboratory against these ranges:

On the sterol side, total β-sitosterol runs 95.9-96.41% and total sitosterol 2,446.6-2,638.4 mg/kg.

Phenolic compounds

Hydroxytyrosol and tyrosol carry the oil's bitterness and pungency along with its oxidative stability. We looked at what this family does in oleocanthal and polyphenols.

The sensory definition

The certificate also describes the taste, and the terms are not arbitrary: the fruity aromas are fresh grass, artichoke, green almond, green tomato, green apple, green plum. The most general are green grass and artichoke.

Bitterness and pungency are usually mild to moderate, and can be intense in early-harvest oils. We weighed up whether early harvest is expensive or valuable elsewhere.

There is also a threshold: each of the three positive attributes (fruitiness, bitterness, pungency) must have a median ≥1 and their sum ≥5, with no negative attribute present.

Where the distinctiveness comes from

The certificate explains the geography through three elements:

The mountains. The Madra range acts as a natural windbreak against the prevailing northerlies that olive growing does not want. Together with the Kaz mountains it shapes the air currents.

*The imbat. The humid wind off the northern Aegean mixes with oxygen from the rich vegetation on the mountains and settles over the trees as a mist. According to the certificate this is the mechanism that protects the region's olives from drought even in the driest years*.

The soil. Sandy, loamy, calcareous Mediterranean soil, generally neutral in pH.

The raw material is defined too: the fruit is cylindrical and medium-sized, with 85% flesh and 25% oil.

The production method

The olives are harvested without touching the ground, carried in crates and reach the mill the same day. Extraction may be traditional (water press or steel press) or by continuous system.

The "same day" provision may look minor, but holding olives is the principal cause of rising acidity.

The rule on use

The name appears on the packaging together with a designation-of-origin emblem and a hologram, each carrying its own serial number. Where it cannot be applied to packaging, the logo is used on sealed tanks.

The serialised hologram is the traceability leg of the registration.

In short

The name Ayvalık Olive Oil belongs to extra virgin oil from one district, one cultivar, pressed the same day, and meeting fourteen separate chemical criteria. The certificate does not say "regional" — it says measurable.

Source: Turkish Patent and Trademark Office, Geographical Indication Registration Certificate No 88 — Ayvalık Zeytinyağı.