Thousands of years ago, the ancient Egyptians referred to honey as the food of the gods. But not all honey is the same. It owes its broad spectrum of colour, taste, aroma and ingredients to the nectar collected by bees from various flowering plants. Honey pollen analysis is an essential analytical method for determining which flowers the bees have visited. It also indicates whether honeydew is present in addition to nectar.

In addition to sensory and chemical-physical analysis, honey pollen analysis is the third mainstay for determining the geographical origin and varietal purity of honey, utilising the fact that every plant visited by a bee leaves its fingerprint in the honey in the form of a pollen typical of each plant species. The number or composition of the individual pollen can be used to determine the geographical origin and possible varietal purity of the honey.

It is also used to help beekeepers decide whether to declare the honey as varietal honey, as the honey jar must always contain the type of honey stated on the label. An incorrect declaration can lead to severe penalties from the food authorities.

How does the pollen get into the nectar or honey?

• Primary dusting: This is the pollen that is introduced into the honey by the bee during nectar collection.
• Secondary dusting: The pollen enters the honeycomb cell via the bee's hair coat or the pollen puffs and thus also into the honey.
• Tertiary atomisation: The pollen enters the honey during the spinning process or, in the case of pressed honey, through bee bread.

Neither secondary nor tertiary dusting allow conclusions to be drawn about the honey supply.

The size of a pollen grain varies between approx. 5 µm (5 thousandths of a millimetre) and 150 µm (Fig. 1). One gram of honey usually contains a few hundred to several thousand pollen grains. However, not every plant leaves the same amount of pollen in the nectar. This depends on the inflorescence of the plant.

If the flower is upright, the pollen falls down into the nectar at the base of the flower when touched or blown by the wind and is thus picked up by the bee when collecting nectar (Fig. 2). If it hangs downwards (Fig. 3), most of the pollen falls onto the edge of the flower or out of the flower. This leaves little pollen in the nectar, which the bees bring into the hive. This is referred to as over- or under-represented plant species. This circumstance is taken into account when assessing botanical origin. (Bandion and Pechhacker, 2003 Methodenbuch zur Honigprüfung in Österreich, ISBN 3-200-00072-4).

There are basically three different pollen donors:

• Nectar plants: plants that produce nectar and pollen (rape, sunflower, dandelion, etc.)
• Nectarless plants: Plants that only produce pollen (plantain, maize, sour grasses, etc.)
• Wind-borne plants: Plants whose pollen is carried by the wind and thus ends up in the nectar or honeydew (spruce, alder, birch, etc.)

Lime blossom honey from the Spargelfeldstraße location (harvest 2025): A full pollen analysis of the honey sample was carried out. All pollen forms were identified, listed and then 1,000 pollen grains were counted. Based on the result of the pollen analysis, the honey with a lime pollen content of 2.6 % can be labelled as "lime blossom honey".

In the course of the analysis, a total of 35 different pollen forms were detected in the honey sample. The variety of pollen found makes the honey a typical honey from the north-eastern outskirts of Vienna: the bees collected pollen from the surrounding gardens and parks as well as from the fields of the Marchfeld. The honey therefore contains pollen from various fruit trees, lime trees, maples and lilacs, as well as the tree of heaven , which is typical of eastern Austria. Various pollen from field and roadside herbs, such as different cruciferous plants, umbelliferous plants and plantain plants complete the pollen spectrum. In addition, our pollen experts Sarah Oberleitner and Julia Hoffmann were also able to find pollen from another special plant in the honey: "We were also able to find isolated pollen from strawberries in our AGES honey. This most likely came from the neighbouring gardens and the large strawberry field nearby." This wide variety of pollen types makes the honey from the Spargelfeldstraße something very special.

With a share of 57.0 %, the most common type of pollen comes from the tree of heaven(Ailanthus altissima). The approximately 21-25 µm large pollen grain is characterised by its round shape, a furrowed surface and three germination sites, which are formed into pore folds (see illustration).

The pollen that gives honey its name, which comes from lime trees(Tilia spp.), is slightly larger at 21-35 µm. The surface is reticulated and the three characteristic germination sites are formed as short pore folds (see illustration).

The special strawberry pollen(Fragaria spp.) is about 21-25 µm in size. Similar to the pollen of the tree of heaven, it also has a furrowed surface and three germination centres that are formed into pore folds. Nevertheless, the two pollen forms can be easily distinguished visually (see illustration).

Although the pollen of the tree of heaven is present in a larger proportion than the lime pollen, the honey can still be described as lime blossom honey. This is because there is generally little pollen in lime nectar. Lime pollen is therefore underrepresented, which is why a honey can be labelled as lime blossom honey if it contains as little as 1% lime pollen. In addition, there is currently no description of varieties for honey from the tree of heaven in Austria in the underlying assessment literature.

Lime blossom honey from the Spargelfeldstraße location (harvest 2024): A full pollen analysis of the honey sample was carried out. All pollen forms were identified, listed and then 1,000 pollen grains were counted. Based on the result of the pollen analysis, the honey with a lime pollen content of 7.8% can be labelled as "lime blossom honey".

In the course of the analysis, a total of 36 different pollen forms were detected in the honey sample. The variety of pollen found makes the honey a typical honey from the north-eastern outskirts of Vienna: the bees collected pollen from the surrounding gardens and parks as well as from the fields of the Marchfeld. The honey therefore contains pollen from various fruit trees, lime trees, maples and lilacs as well as garden asparagus from the surrounding fields. Various pollen from field and roadside herbs, such as different cruciferous plants, composite plants and plantain plants complete the pollen spectrum. According to our pollen expert Sarah Oberleitner, there is also another pollen that makes honey special: "I mainly find pollen from the tree of heaven in Eastern Austrian honeys. This makes the honey typical for Vienna." This wide variety of pollen types makes the honey from Spargelfeldstraße something very special.

With a share of 25.4%, the most common type of pollen comes from the tree of heaven(Ailanthus altissima). The approximately 21-25µm large pollen grain is characterised by its round shape, a furrowed surface and three germination sites, which are formed into pore folds (see illustration).

The pollen that gives honey its name, which comes from lime trees(Tilia sp.), is slightly larger at 21-35µm. The surface is reticulated and the three characteristic germination sites are formed as short pore folds (see illustration).

The pollen of the garden asparagus(Asparagus officinales), which matches the location by name, is round and about 21-25µm in size. The surface structure cannot be clearly determined with a light microscope. The germination site is formed as a fold and is located at the distal pole of the pollen grain (see illustration).
Although the pollen of the tree of heaven is present in a larger proportion than the lime pollen, the honey can still be described as lime blossom honey. This is because there is generally less pollen in lime nectar. Lime pollen is therefore underrepresented, which is why a honey can be labelled as lime blossom honey if it contains as little as 1% lime pollen.