How to Identify Real Gemlik Olives?

Almost every black olive you see in the market or on the shelves of the supermarket is offered under the name "Gemlik olives". This creates confusion for the consumer. So how can we distinguish real Gemlik olives from fakes?

Origin – Geographical Indication

Gemlik olives are a product with a geographical indication, grown only in the Gemlik region of Bursa. The packaging should bear the phrase " Gemlik olive", not " Gemlik type ", and the geographical indication logo and the banderol given by the Gemlik Chamber of Commerce specific to the company. The Geographical Indication logo can easily be printed on the labels by malicious sellers, so the banderol should definitely be checked. The current list of the Gemlik Chamber of Commerce is as follows;

It can be checked on the page https://www.gemliktb.org.tr/cografi-isaret under the title Our Members/Our members who use geographical indications.

The screenshot dated 15/01/2025 is as follows,

There are three elements that companies that are entitled to use geographical indications must have on their packaging:

Gemlik olive logo, geographical indication registration logo and QR code hologram

You have purchased an olive product and it says "Gemlik Olive". However, some basic elements are missing on the label or there is only a Geographical Indication logo. In this case, you may be confused. Don't worry; you can access the current authorized producer list of Gemlik Chamber of Commerce via the link we provided above. If the producer name is not on the list, the use of this logo on the label is actually invalid. You can complain by reporting the situation to Gemlik Chamber of Commerce.

The characteristic features specifically specified for Gemlik Olives by the Gemlik Chamber of Commerce when registering the designation of origin are as follows:

Description and Distinctive Features of the Product:

Gemlik Olives are table olives with a color ranging from burgundy to black, thin skin, thick flesh, small and elliptical seeds, and whole grains. Gemlik Olives are produced from the ripe fruits of Gemlik, Gemlik 21 and Gemlik 27 varieties belonging to the Olea europaea L. species of the Oleaceae family.

Gemlik Olives are processed with the “brine” method, which is produced by blending ripe olives with water and sea salt and applying pressure with granite stones, or with the “sele” method, which is produced by using sea salt or rock salt. These olives, which are prepared without using sea or rock salt in the processing of olives, are called “dry sele”. In some cases, corn oil or sunflower oil can be used in addition to salt in the processing of olives. In this case, the olives are called “oiled sele”.

Gemlik Olives are naturally fermented without any alkali treatment. Gemlik Olives should be fresh and uncrushed. The ratio between flesh and seed varies between 6/1 and 7/1. Gemlik Olives have thin skin and are attached to the flesh. Their seeds are small and medium sized. The size of the olives varies between 201-410 seeds per kilogram. Gemlik Olives contain 28-35% oil.

Some characteristics of Gemlik Olive:

• Olive size: Up to 410 fruits/kg

• Salt Content: Maximum 12% (in brine), maximum 8% for pickled olives (in the olive body), maximum 4% for dry and oily olives (in the olive body)

• Smell: It does not contain any foreign odor other than the natural odor of the olive.

• Taste: Does not contain fermented or foreign flavors.

• Processed fruit hardness: 8-12 kg/cm²

• The olives offered for sale do not contain any foreign matter.

• Organic foreign matter (broken olive stems and leaves etc.): Maximum 3 pieces in 1 kg.

• Processed “Gemlik Olives” , according to the number of fruits per kg:

  • Olives between 201-230 (XL),

  • 231-260 (L),

  • 261-290 (M),

  • 291-320 (S),

  • 321-350 (XS),

  • 351-380 (2XS)

  • and are graded according to their size as 381-410 (3XS).

The characteristics of Gemlik Olive are affected by the temperature and precipitation conditions of the geographical border, altitude and soil structure. These characteristics are due to the sheltered bays of Gemlik and Mudanya districts, and the fact that Orhangazi and İznik districts are close to the gulf and are located around the lake. The geographical border has transitional climate characteristics. The average daily temperature is a minimum of 5.8 °C in January and 6.8 °C in February, which is suitable for the period when the plant needs cold. The lowest temperature in May, which is the flowering period, is an average of 16.9 °C and the lowest temperature in the fruit formation period is an average of 21.1 °C. These temperature values are close to optimum growing conditions for olive trees and provide high olive yields.

Temperature affects the Gemlik Olive's skin thickness and the adhesion of the skin to the flesh. In addition, the transition climate feature of the geographical border causes lower temperatures during the olive's growth phase. Due to the transition climate, the low temperatures during the olive's growth phase cause the Gemlik Olive to be both thin-skinned and the skin to adhere tightly to the flesh. Thus, the fruit skin is not felt when eating the Gemlik Olive.

Temperature, altitude and variety characteristics affect the amount of terpenes (aromatic compounds) in the fruit. The amount of terpenes also affects the taste. The average altitude of the geographical border is 112 m above sea level, and at this altitude, the level of “Cyclogeraniol”, which is a grassy and sweet compound of olives, and “(E,E)-a-Farnesene”, which is a negative aroma, were found to be higher than in hot regions. There is a difference of approximately 4,000-5,000 ppm in terms of terpene amount between the Gemlik region and other regions.

The region’s rainfall regime affects the yield and quality of the crop. Approximately 61.8 mm of rainfall in April affects yield, while 43.7 mm in September affects olive size and oil content. The soil composition of the geographical border is approximately 63% clay loam, 20% loam and 17% clayey. This soil structure supports the root development of olive trees, allowing optimum yield and quality.

This brief information article will help you understand whether the olive you purchased is really Gemlik Olive in the light of the most up-to-date data. Because unfortunately, many products sold under the name "Gemlik Olive" in the market mislead the consumer even though they do not have the right to use this name. Despite approximately 300 active members registered with the Gemlik Chamber of Commerce, only 28 companies have the authority to use geographical indication as of April 15, 2025. Therefore, it is not enough to just write "Gemlik Olive" on the label of the olive you buy. In order to understand whether it is real Gemlik Olive, it is definitely necessary to check whether the name of the producer company is on the current authorized producer list of the Gemlik Chamber of Commerce. Otherwise, even the inclusion of the geographical indication logo on the label can be misleading. Real Gemlik Olive is distinguished by its place of production, processing method, quality and characteristic features. As a consumer, you can both bring quality to your table and protect the reputation of this valuable product by making conscious choices.