Bee Bread (Perga)

Bee bread (perga) is pollen that bees pack into comb cells for storage, mixed with honey and secretions and slightly acidified over time; it is the protein store the colony uses to rear brood. In human nutrition it is eaten as a highly nutritious product, but human studies on its health effects are very limited. Because it is derived from pollen, it carries a risk of allergy.

What is bee bread and how is it formed?

Foragers usually deposit the pollen pellets from their legs in cells near the brood area. House bees press these pellets into the cell with their heads and add nectar or honey and secretions on top. The cells are usually not capped with wax; the top surface is covered with a thin layer of honey.

Inside the cell, lactic acid bacteria and yeasts carried on the pollen and nectar multiply. The acidity rises, which allows the pollen to be stored without going mouldy or spoiling. In one cell, pollen from several different days and plants can form layers on top of each other.

The difference between perga and raw pollen

The classic account says that the acidification process partly breaks down the pollen wall, making the contents more digestible and increasing the nutritional value. Recent research partly questions this picture: there are findings that stored pollen does not undergo a very great chemical transformation, that the main function of the process is preservation, and that bees prefer freshly stored pollen. The subject is still being researched.

Where is bee bread found in the hive?

In a healthy brood frame, perga usually lies in a band around the brood area, between the brood and the honey. This arrangement lets nurse bees reach protein easily.

For the beekeeper this band is an indicator of health: seeing plenty of perga around the brood area in spring shows that the colony is ready to build up. In a colony whose perga stores have run down and whose pollen band has thinned, brood rearing slows.

How is perga harvested? Step by step

Because perga sits inside the cell, surrounded by wax, harvesting it requires processing the comb. Production should therefore be combined with a plan for renewing old combs.

1. Choosing frames: Broodless frames full of perga are selected for removal from the hive. Enough perga is left for the colony's own needs.
2. Treatment check: Perga is not taken from frames filled during a varroa treatment period; the risk of residues is higher in old combs that have had a lot of contact with treatments.
3. Freezing: The frames are frozen. This both makes the wax brittle and kills the eggs and larvae of wax moths.
4. Separating: The frozen comb is cut and broken up; the perga granules are separated from the wax with sieves or special separating equipment. This gives hexagonal pellets that keep the shape of the cell.
5. Drying: If necessary, moisture is removed at a low temperature with air flow.
6. Cleaning and packing: Wax crumbs are picked out, and the perga is put into airtight containers.

How should perga be stored?

• An airtight container: Perga that absorbs moisture goes mouldy.
• A cool, dark, dry place: Heat and light lower the quality.
• Freezing for long-term storage: This preserves nutritional value and freshness.
• Storing in the frame: If spare frames full of perga are to be stored outside the hive, they should be kept cold to protect them from wax moths and pollen mites.

Is bee bread healthy? The state of the evidence

Perga is a highly nutritious product containing protein, amino acids, carbohydrates, fatty acids, some vitamins, minerals and phenolic compounds. By contrast, studies in humans on specific health effects are very few; current knowledge rests largely on laboratory and animal studies. It is therefore accurate to say "a nourishing food; evidence for health effects is limited".

• Allergy: Because it is derived from pollen, it can cause allergic reactions. People with a pollen allergy, asthma or an allergy to bee products should not use it without consulting a doctor.
• First use: A common recommendation is to start with a very small amount.
• Children, pregnancy, breastfeeding, chronic illness: Consult a doctor before using it as a supplement.

Common mistakes

• Harvesting the colony's entire spring protein store.
• Taking perga from combs filled during treatment periods or from very old combs.
• Frames full of perga stored without freezing becoming overrun with wax moths.
• Leaving perga uncovered in a damp place.
• Promoting the product with expressions such as "medicine" or "cures diseases".